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Aparicio JG, Hopp H, Harutyunyan N, Stewart C, Cobrinik D, Borchert M. Aberrant gene expression yet undiminished retinal ganglion cell genesis in iPSC-derived models of optic nerve hypoplasia. Ophthalmic Genet 2024; 45:1-15. [PMID: 37807874 PMCID: PMC10841193 DOI: 10.1080/13816810.2023.2253902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/26/2023] [Indexed: 10/10/2023]
Abstract
BACKGROUND Optic nerve hypoplasia (ONH), the leading congenital cause of permanent blindness, is characterized by a retinal ganglion cell (RGC) deficit at birth. Multifactorial developmental events are hypothesized to underlie ONH and its frequently associated neurologic and endocrine abnormalities; however, environmental influences are unclear and genetic underpinnings are unexplored. This work investigates the genetic contribution to ONH RGC production and gene expression using patient induced pluripotent stem cell (iPSC)-derived retinal organoids (ROs). MATERIALS AND METHODS iPSCs produced from ONH patients and controls were differentiated to ROs. RGC genesis was assessed using immunofluorescence and flow cytometry. Flow-sorted BRN3+ cells were collected for RNA extraction for RNA-Sequencing. Differential gene expression was assessed using DESeq2 and edgeR. PANTHER was employed to identify statistically over-represented ontologies among the differentially expressed genes (DEGs). DEGs of high interest to ONH were distinguished by assessing function, mutational constraint, and prior identification in ONH, autism and neurodevelopmental disorder (NDD) studies. RESULTS RGC genesis and survival were similar in ONH and control ROs. Differential expression of 70 genes was identified in both DESeq2 and edgeR analyses, representing a ~ 4-fold higher percentage of DEGs than in randomized study participants. DEGs showed trends towards over-representation of validated NDD genes and ONH exome variant genes. Among the DEGs, RAPGEF4 and DMD had the greatest number of disease-relevant features. CONCLUSIONS ONH genetic background was not associated with impaired RGC genesis but was associated with DEGs exhibiting disease contribution potential. This constitutes some of the first evidence of a genetic contribution to ONH.
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Affiliation(s)
- Jennifer G. Aparicio
- The Vision Center and The Saban Research Institute,
Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Hanno Hopp
- The Vision Center and The Saban Research Institute,
Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Narine Harutyunyan
- The Vision Center and The Saban Research Institute,
Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Carly Stewart
- The Vision Center and The Saban Research Institute,
Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - David Cobrinik
- The Vision Center and The Saban Research Institute,
Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Department of Biochemistry & Molecular Medicine, Keck
School of Medicine, University of Southern California, Los Angeles, CA, USA
- Norris Comprehensive Cancer Center, Keck School of
Medicine, University of Southern California, Los Angeles, CA, USA
- USC Roski Eye Institute, Department of Ophthalmology, Keck
School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Mark Borchert
- The Vision Center and The Saban Research Institute,
Children’s Hospital Los Angeles, Los Angeles, CA, USA
- USC Roski Eye Institute, Department of Ophthalmology, Keck
School of Medicine, University of Southern California, Los Angeles, CA, USA
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2
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Bertke MM, Dubiak KM, Cronin L, Zeng E, Huber PW. A deficiency in SUMOylation activity disrupts multiple pathways leading to neural tube and heart defects in Xenopus embryos. BMC Genomics 2019; 20:386. [PMID: 31101013 PMCID: PMC6525467 DOI: 10.1186/s12864-019-5773-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 05/03/2019] [Indexed: 02/08/2023] Open
Abstract
Background Adenovirus protein, Gam1, triggers the proteolytic destruction of the E1 SUMO-activating enzyme. Microinjection of an empirically determined amount of Gam1 mRNA into one-cell Xenopus embryos can reduce SUMOylation activity to undetectable, but nonlethal, levels, enabling an examination of the role of this post-translational modification during early vertebrate development. Results We find that SUMOylation-deficient embryos consistently exhibit defects in neural tube and heart development. We have measured differences in gene expression between control and embryos injected with Gam1 mRNA at three developmental stages: early gastrula (immediately following the initiation of zygotic transcription), late gastrula (completion of the formation of the three primary germ layers), and early neurula (appearance of the neural plate). Although changes in gene expression are widespread and can be linked to many biological processes, three pathways, non-canonical Wnt/PCP, snail/twist, and Ets-1, are especially sensitive to the loss of SUMOylation activity and can largely account for the predominant phenotypes of Gam1 embryos. SUMOylation appears to generate different pools of a given transcription factor having different specificities with this post-translational modification involved in the regulation of more complex, as opposed to housekeeping, processes. Conclusions We have identified changes in gene expression that underlie the neural tube and heart phenotypes resulting from depressed SUMOylation activity. Notably, these developmental defects correspond to the two most frequently occurring congenital birth defects in humans, strongly suggesting that perturbation of SUMOylation, either globally or of a specific protein, may frequently be the origin of these pathologies. Electronic supplementary material The online version of this article (10.1186/s12864-019-5773-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michelle M Bertke
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, 46556, USA.,Present Address: College of Computer, Mathematical, and Natural Sciences, University of Maryland, College Park, MD, 20742, USA
| | - Kyle M Dubiak
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, 46556, USA
| | - Laura Cronin
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana, 46556, USA
| | - Erliang Zeng
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana, 46556, USA.,Present Address: Division of Biostatistics and Computational Biology, Iowa Institute for Oral Health Research, University of Iowa, Iowa City, IA, 52242, USA.,Present Address: Department of Preventive & Community Dentistry, College of Dentistry, University of Iowa, Iowa City, IA, 52242, USA.,Present Address: Department of Biostatistics, University of Iowa, Iowa City, IA, 52242, USA.,Present Address: Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - Paul W Huber
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, 46556, USA. .,Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana, USA. .,Center for Stem Cells and Regenerative Medicine, University of Notre Dame, Notre Dame, Indiana, 46556, USA.
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Xia S, Qu J, Jia H, He W, Li J, Zhao L, Mao M, Zhao Y. Overexpression of Forkhead box C1 attenuates oxidative stress, inflammation and apoptosis in chronic obstructive pulmonary disease. Life Sci 2018; 216:75-84. [PMID: 30428305 DOI: 10.1016/j.lfs.2018.11.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 11/02/2018] [Accepted: 11/10/2018] [Indexed: 02/06/2023]
Abstract
AIM Chronic obstructive pulmonary disease (COPD) is a disease caused by cigarette smoke, which has been emerging as a serious health problem worldwide. The aim of this study is to explore the mRNA expression profile of lung tissues from the COPD rats and to characterize the role of Forkhead box C1 (Foxc1) in COPD. MAIN METHODS Wistar rats were exposed to cigarette smoke during 16 weeks for COPD model establishment. The microarray was used to identify the differential gene expression in the lung of rats. Adenovirus carrying Foxc1 was administered to rats by intratracheally instillation once a week for 16 weeks. Human bronchial epithelial cell line (16HBE) cells were transfected with Foxc1 siRNA followed by incubation in the presence of CSE (10%) for 24 h. Subsequently, the pathological changes, fibrosis, apoptosis, inflammatory cytokines and oxidative stress were detected. KEY FINDINGS Microarray results showed an upregulation of Foxc1 in lung tissues in COPD rats. Overexpression of Foxc1 mitigated the lung injury, as evidenced by reducing alveolar fusion, inflammatory cell infiltration and oxidative stress. Additionally, the apoptosis was remarkably increased in the lung in rats exposed to cigarette smoke, which was suppressed by Foxc1 overexpression. Furthermore, downregulation of Foxc1 aggravated the inflammation, oxidative stress and apoptosis in 16HBE cells with CSE treatment. SIGNIFICANCE Overexpression of Foxc1 could prevent oxidative stress, inflammation responses and cell apoptosis and knockdown of Foxc1 has the opposite effect, suggesting that Foxc1 may be available for lung protection during COPD.
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Affiliation(s)
- Shuyue Xia
- Department of Respiratory and Critical Care Medicine, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, People's Republic of China.
| | - Jian Qu
- Shenyang Environmental Monitor Central Station, Shenyang 110016, People's Republic of China
| | - Hui Jia
- Department of Respiratory and Critical Care Medicine, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, People's Republic of China
| | - Wei He
- Department of Respiratory and Critical Care Medicine, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, People's Republic of China
| | - Jing Li
- Shenyang Environmental Monitor Central Station, Shenyang 110016, People's Republic of China
| | - Long Zhao
- Department of Respiratory and Critical Care Medicine, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, People's Republic of China
| | - Mingqing Mao
- Department of Respiratory and Critical Care Medicine, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, People's Republic of China
| | - Yan Zhao
- Department of Respiratory and Critical Care Medicine, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, People's Republic of China
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Song Y, Sun B, Hao L, Hu J, Du S, Zhou X, Zhang L, Liu L, Gong L, Chi X, Liu Q, Shao S. Elevated eukaryotic elongation factor 2 expression is involved in proliferation and invasion of lung squamous cell carcinoma. Oncotarget 2018; 7:58470-58482. [PMID: 27542262 PMCID: PMC5295444 DOI: 10.18632/oncotarget.11298] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/27/2016] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic elongation factor 2 (EF2), is a critical enzyme solely responsible for catalyzing the translocation of the elongated peptidyl-tRNA from the A to P sites of the ribosome during the process of protein synthesis. EF2 is found to be highly expressed in a variety of malignant tumors and is correlated with cancer cell progression and recurrence. The present study was designed to uncover the function of EF2 on lung squamous cell carcinoma (LSCC) cancer cell growth and progression. Our results from clinical tissue studies showed that EF2 protein was significantly overexpressed in LSCC tissues, compared with the adjacent normal lung tissues, which was confirmed by western blotting and tissue microarray. Forced expression of EF2 resulted in the enhancement of lung squamous carcinoma NCI-H520 cells growth through promotion of G2/M progression in cell cycle, activating Akt and Cdc2/Cyclin B1. In nude mice cancer xenograft model, overexpression of EF2 significantly facilitated cell proliferation in vivo. Furthermore, forced expression of EF2 in the cells increased the capabilities of migration and invasion by changing the expressions of EMT-related proteins and genes. These results provided novel insights into the role of EF2 in tumorigenesis and progression in LSCC. EF2-targeted therapy could become a good strategy for the clinical treatment of LSCC.
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Affiliation(s)
- Yang Song
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - Bing Sun
- Department of Chest Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - LiHong Hao
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - Jun Hu
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - Sha Du
- Institute of Cancer Stem Cell, Dalian Medical University Cancer Center, Liaoning, China
| | - Xin Zhou
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - LiYuan Zhang
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - Lu Liu
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - LinLin Gong
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - XinMing Chi
- Department of Histology and Embryology, Dalian Medical University, Dalian, China
| | - Qiang Liu
- Institute of Cancer Stem Cell, Dalian Medical University Cancer Center, Liaoning, China
| | - ShuJuan Shao
- Department of Histology and Embryology, Dalian Medical University, Dalian, China.,Liaoning Key Laboratory of Proteomics, Dalian Medical University, Liaoning, China
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Lienkamp SS. Using Xenopus to study genetic kidney diseases. Semin Cell Dev Biol 2016; 51:117-24. [PMID: 26851624 DOI: 10.1016/j.semcdb.2016.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
Abstract
Modern sequencing technology is revolutionizing our knowledge of inherited kidney disease. However, the molecular role of genes affected by the rapidly rising number of identified mutations is lagging behind. Xenopus is a highly useful, but underutilized model organism with unique properties excellently suited to decipher the molecular mechanisms of kidney development and disease. The embryonic kidney (pronephros) can be manipulated on only one side of the animal and its formation observed directly through the translucent skin. The moderate evolutionary distance between Xenopus and humans is a huge advantage for studying basic principles of kidney development, but still allows us to analyze the function of disease related genes. Optogenetic manipulations and genome editing by CRISPR/Cas are exciting additions to the toolbox for disease modelling and will facilitate the use of Xenopus in translational research. Therefore, the future of Xenopus in kidney research is bright.
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Affiliation(s)
- Soeren S Lienkamp
- Renal Division, Department of Medicine, University of Freiburg Medical Center, Hugstetter Straße 55, 79106 Freiburg, Germany; Center for Biological Signaling Studies (BIOSS), Albertstraße 19, 79104 Freiburg, Germany.
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Sánchez RS, Sánchez SS. Paraxis is required for somite morphogenesis and differentiation in Xenopus laevis. Dev Dyn 2015; 244:973-87. [PMID: 26010523 DOI: 10.1002/dvdy.24294] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 05/01/2015] [Accepted: 05/02/2015] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND In most vertebrates, the segmentation of the paraxial mesoderm involves the formation of metameric units called somites through a mesenchymal-epithelial transition. However, this process is different in Xenopus laevis because it does not form an epithelial somite. Xenopus somitogenesis is characterized by a complex cells rearrangement that requires the coordinated regulation of cell shape, adhesion, and motility. The molecular mechanisms that control these cell behaviors underlying somite formation are little known. Although the Paraxis has been implicated in the epithelialization of somite in chick and mouse, its role in Xenopus somite morphogenesis has not been determined. RESULTS Using a morpholino and hormone-inducible construction approaches, we showed that both gain and loss of function of paraxis affect somite elongation, rotation and alignment, causing a severe disorganization of somitic tissue. We further found that depletion or overexpression of paraxis in the somite led to the downregulation or upregulation, respectively, of cell adhesion expression markers. Finally, we demonstrated that paraxis is necessary for the proper expression of myotomal and sclerotomal differentiation markers. CONCLUSIONS Our results demonstrate that paraxis regulates the cell rearrangements that take place during the somitogenesis of Xenopus by regulating cell adhesion. Furthermore, paraxis is also required for somite differentiation.
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Affiliation(s)
- Romel Sebastián Sánchez
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán (T4000ILI), Argentina
| | - Sara Serafina Sánchez
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, San Miguel de Tucumán (T4000ILI), Argentina
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7
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Szabó NE, Haddad-Tóvolli R, Zhou X, Alvarez-Bolado G. Cadherins mediate sequential roles through a hierarchy of mechanisms in the developing mammillary body. Front Neuroanat 2015; 9:29. [PMID: 25852491 PMCID: PMC4365714 DOI: 10.3389/fnana.2015.00029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 02/25/2015] [Indexed: 11/13/2022] Open
Abstract
Expression of intricate combinations of cadherins (a family of adhesive membrane proteins) is common in the developing central nervous system. On this basis, a combinatorial cadherin code has long been proposed to underlie neuronal sorting and to be ultimately responsible for the layers, columns and nuclei of the brain. However, experimental proof of this particular function of cadherins has proven difficult to obtain and the question is still not clear. Alternatively, non-specific, non-combinatorial, purely quantitative adhesive differentials have been proposed to explain neuronal sorting in the brain. Do cadherin combinations underlie brain cytoarchitecture? We approached this question using as model a well-defined forebrain nucleus, the mammillary body (MBO), which shows strong, homogeneous expression of one single cadherin (Cdh11) and patterned, combinatorial expression of Cdh6, −8 and −10. We found that, besides the known combinatorial Cdh pattern, MBO cells are organized into a second, non-overlapping pattern grouping neurons with the same date of neurogenesis. We report that, in the Foxb1 mouse mutant, Cdh11 expression fails to be maintained during MBO development. This disrupted the combination-based as well as the birthdate-based sorting in the mutant MBO. In utero RNA interference (RNAi) experiments knocking down Cdh11 in MBO-fated migrating neurons at one specific age showed that Cdh11 expression is required for chronological entrance in the MBO. Our results suggest that neuronal sorting in the developing MBO is caused by adhesion-based, non-combinatorial mechanisms that keep neurons sorted according to birthdate information (possibly matching them to target neurons chronologically sorted in the same manner). Non-specific adhesion mechanisms would also prevent cadherin combinations from altering the birthdate-based sorting. Cadherin combinations would presumably act later to support specific synaptogenesis through specific axonal fasciculation and final target recognition.
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Affiliation(s)
- Nora-Emöke Szabó
- Department Neurobiology and Development, Neural Circuit Development Unit, IRCM Montréal, QC, Canada
| | | | - Xunlei Zhou
- Department of Neuroanatomy, University of Heidelberg Heidelberg, Germany
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Cizelsky W, Tata A, Kühl M, Kühl SJ. The Wnt/JNK signaling target gene alcam is required for embryonic kidney development. Development 2014; 141:2064-74. [PMID: 24764076 DOI: 10.1242/dev.107938] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Proper development of nephrons is essential for kidney function. β-Catenin-independent Wnt signaling through Fzd8, Inversin, Daam1, RhoA and Myosin is required for nephric tubule morphogenesis. Here, we provide a novel mechanism through which non-canonical Wnt signaling contributes to tubular development. Using Xenopus laevis as a model system, we found that the cell-adhesion molecule Alcam is required for proper nephrogenesis and functions downstream of Fzd3 during embryonic kidney development. We found alcam expression to be independent of Fzd8 or Inversin, but to be transcriptionally regulated by the β-Catenin-independent Wnt/JNK pathway involving ATF2 and Pax2 in a direct manner. These novel findings indicate that several branches of Wnt signaling are independently required for proximal tubule development. Moreover, our data indicate that regulation of morphogenesis by non-canonical Wnt ligands also involves direct transcriptional responses in addition to the effects on a post-translational level.
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Affiliation(s)
- Wiebke Cizelsky
- Institute for Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
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9
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Maguire RJ, Isaacs HV, Pownall ME. Early transcriptional targets of MyoD link myogenesis and somitogenesis. Dev Biol 2012; 371:256-68. [PMID: 22954963 DOI: 10.1016/j.ydbio.2012.08.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 07/10/2012] [Accepted: 08/22/2012] [Indexed: 12/20/2022]
Abstract
In order to identify early transcriptional targets of MyoD prior to skeletal muscle differentiation, we have undertaken a transcriptomic analysis on gastrula stage Xenopus embryos in which MyoD has been knocked-down. Our validated list of genes transcriptionally regulated by MyoD includes Esr1 and Esr2, which are known targets of Notch signalling, and Tbx6, mesogenin, and FoxC1; these genes are all are known to be essential for normal somitogenesis but are expressed surprisingly early in the mesoderm. In addition we found that MyoD is required for the expression of myf5 in the early mesoderm, in contrast to the reverse relationship of these two regulators in amniote somites. These data highlight a role for MyoD in the early mesoderm in regulating a set of genes that are essential for both myogenesis and somitogenesis.
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Affiliation(s)
- Richard J Maguire
- Biology Department, University of York, Heslington, York, North Yorkshire YO10 5YW, UK
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Novel roles of the chemorepellent axon guidance molecule RGMa in cell migration and adhesion. Mol Cell Biol 2012; 32:968-80. [PMID: 22215618 DOI: 10.1128/mcb.06128-11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The repulsive guidance molecule A (RGMa) is a contact-mediated axon guidance molecule that has significant roles in central nervous system (CNS) development. Here we have examined whether RGMa has novel roles in cell migration and cell adhesion outside the nervous system. RGMa was found to stimulate cell migration from Xenopus animal cap explants in a neogenin-dependent and BMP-independent manner. RGMa also stimulated the adhesion of Xenopus animal cap cells, and this adhesion was dependent on neogenin and independent of calcium. To begin to functionally characterize the role of specific domains in RGMa, we assessed the migratory and adhesive activities of deletion mutants. RGMa lacking the partial von Willebrand factor type D (vWF) domain preferentially perturbed cell adhesion, while mutants lacking the RGD motif affected cell migration. We also revealed that manipulating the levels of RGMa in vivo caused major migration defects during Xenopus gastrulation. We have revealed here novel roles of RGMa in cell migration and adhesion and demonstrated that perturbations to the homeostasis of RGMa expression can severely disrupt major morphogenetic events. These results have implications for understanding the role of RGMa in both health and disease.
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Colleoni S, Galli C, Gaspar JA, Meganathan K, Jagtap S, Hescheler J, Sachinidis A, Lazzari G. Development of a neural teratogenicity test based on human embryonic stem cells: response to retinoic acid exposure. Toxicol Sci 2011; 124:370-7. [PMID: 21934132 DOI: 10.1093/toxsci/kfr245] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The aim of this study was the development of an alternative testing method based on human embryonic stem cells for prenatal developmental toxicity with particular emphasis on early neural development. To this purpose, we designed an in vitro protocol based on the generation of neural rosettes, representing the in vitro counterpart of the developing neural plate and neural tube, and we challenged this complex cell model with retinoic acid (RA), a well-known teratogenic agent. The cells were exposed to different concentrations of RA during the process of rosettes formation. Morphological and molecular parameters were evaluated in treated as compared with untreated cells to detect both cytotoxicity and specific neural toxicity. Transcriptomic analysis was performed with microarray Affymetrix platform and validated by quantitative real-time PCR for genes relevant to early neural development such as HoxA1, HoxA3, HoxB1, HoxB4, FoxA2, FoxC1, Otx2, and Pax7. The results obtained demonstrated that neural rosette forming cells respond to RA with clear concentration-dependent morphological, and gene expression changes remarkably similar to those induced in vivo, in the developing neural tube, by RA exposure. This strict correspondence indicates that the neural rosette protocol described is capable of detecting specific teratogenic mechanisms causing perturbations of early neural development and therefore represents a promising alternative test for human prenatal developmental toxicity.
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Affiliation(s)
- Silvia Colleoni
- Avantea, Laboratory of Reproductive Technologies, 26100 Cremona, Italy.
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Kaltenbrun E, Tandon P, Amin NM, Waldron L, Showell C, Conlon FL. Xenopus: An emerging model for studying congenital heart disease. ACTA ACUST UNITED AC 2011; 91:495-510. [PMID: 21538812 DOI: 10.1002/bdra.20793] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/18/2011] [Accepted: 01/28/2011] [Indexed: 02/02/2023]
Abstract
Congenital heart defects affect nearly 1% of all newborns and are a significant cause of infant death. Clinical studies have identified a number of congenital heart syndromes associated with mutations in genes that are involved in the complex process of cardiogenesis. The African clawed frog, Xenopus, has been instrumental in studies of vertebrate heart development and provides a valuable tool to investigate the molecular mechanisms underlying human congenital heart diseases. In this review, we discuss the methodologies that make Xenopus an ideal model system to investigate heart development and disease. We also outline congenital heart conditions linked to cardiac genes that have been well studied in Xenopus and describe some emerging technologies that will further aid in the study of these complex syndromes.
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Affiliation(s)
- Erin Kaltenbrun
- University of North Carolina McAllister Heart Institute, Chapel Hill, NC 27599, USA
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