1
|
Nunes Santos L, Sousa Costa ÂM, Nikolov M, Carvalho JE, Coelho Sampaio A, Stockdale FE, Wang GF, Andrade Castillo H, Bortoletto Grizante M, Dudczig S, Vasconcelos M, Rosenthal N, Jusuf PR, Nim HT, de Oliveira P, Guimarães de Freitas Matos T, Nikovits W, Tambones IL, Figueira ACM, Schubert M, Ramialison M, Xavier-Neto J. Unraveling the evolutionary origin of the complex Nuclear Receptor Element (cNRE), a cis-regulatory module required for preferential expression in the atrial chamber. Commun Biol 2024; 7:371. [PMID: 38575811 PMCID: PMC10995137 DOI: 10.1038/s42003-024-05972-6] [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: 07/26/2023] [Accepted: 02/26/2024] [Indexed: 04/06/2024] Open
Abstract
Cardiac function requires appropriate proteins in each chamber. Atria requires slow myosin to act as reservoirs, while ventricles demand fast myosin for swift pumping. Myosins are thus under chamber-biased cis-regulation, with myosin gene expression imbalances leading to congenital heart dysfunction. To identify regulatory inputs leading to cardiac chamber-biased expression, we computationally and molecularly dissected the quail Slow Myosin Heavy Chain III (SMyHC III) promoter that drives preferential expression to the atria. We show that SMyHC III gene states are orchestrated by a complex Nuclear Receptor Element (cNRE) of 32 base pairs. Using transgenesis in zebrafish and mice, we demonstrate that preferential atrial expression is achieved by a combinatorial regulatory input composed of atrial activation motifs and ventricular repression motifs. Using comparative genomics, we show that the cNRE might have emerged from an endogenous viral element through infection of an ancestral host germline, revealing an evolutionary pathway to cardiac chamber-specific expression.
Collapse
Affiliation(s)
- Luana Nunes Santos
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
- Australian Regenerative Medicine Institute, Monash University, VIC Australia - Systems Biology Institute, Melbourne, Australia
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil
| | - Ângela Maria Sousa Costa
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Martin Nikolov
- Australian Regenerative Medicine Institute, Monash University, VIC Australia - Systems Biology Institute, Melbourne, Australia
| | - João E Carvalho
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche, Sorbonne Université, CNRS, Villefranche-sur-Mer, France
| | - Allysson Coelho Sampaio
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil
- Faculdade Santa Marcelina - São Paulo, São Paulo, SP, Brazil
| | | | - Gang Feng Wang
- Department of Medicine, Stanford University, Stanford, CA, USA
| | - Hozana Andrade Castillo
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
- Australian Regenerative Medicine Institute, Monash University, VIC Australia - Systems Biology Institute, Melbourne, Australia
| | - Mariana Bortoletto Grizante
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Stefanie Dudczig
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - Michelle Vasconcelos
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil
| | - Nadia Rosenthal
- The Jackson Laboratory, Bar Harbor, Maine, USA
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | - Hieu T Nim
- Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Paulo de Oliveira
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | | | | | - Izabella Luisa Tambones
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Ana Carolina Migliorini Figueira
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Michael Schubert
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche, Sorbonne Université, CNRS, Villefranche-sur-Mer, France
| | - Mirana Ramialison
- Australian Regenerative Medicine Institute, Monash University, VIC Australia - Systems Biology Institute, Melbourne, Australia.
- Murdoch Children's Research Institute, Parkville, VIC, Australia.
| | - José Xavier-Neto
- Department of Morphology, Federal University of Ceará (UFC), Ceará, CE, Brazil.
- Health Scientist-in-Chief of Ceará State, Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico, Ceará, CE, Brazil.
| |
Collapse
|
2
|
Vo L, Schmidtke MW, Da Rosa-Junior NT, Ren M, Schlame M, Greenberg ML. Cardiolipin metabolism regulates expression of muscle transcription factor MyoD1 and muscle development. J Biol Chem 2023; 299:102978. [PMID: 36739949 PMCID: PMC9999232 DOI: 10.1016/j.jbc.2023.102978] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The mitochondrial phospholipid cardiolipin (CL) is critical for numerous essential biological processes, including mitochondrial dynamics and energy metabolism. Mutations in the CL remodeling enzyme TAFAZZIN cause Barth syndrome, a life-threatening genetic disorder that results in severe physiological defects, including cardiomyopathy, skeletal myopathy, and neutropenia. To study the molecular mechanisms whereby CL deficiency leads to skeletal myopathy, we carried out transcriptomic analysis of the TAFAZZIN-knockout (TAZ-KO) mouse myoblast C2C12 cell line. Our data indicated that cardiac and muscle development pathways are highly decreased in TAZ-KO cells, consistent with a previous report of defective myogenesis in this cell line. Interestingly, the muscle transcription factor myoblast determination protein 1 (MyoD1) is significantly repressed in TAZ-KO cells and TAZ-KO mouse hearts. Exogenous expression of MyoD1 rescued the myogenesis defects previously observed in TAZ-KO cells. Our data suggest that MyoD1 repression is caused by upregulation of the MyoD1 negative regulator, homeobox protein Mohawk, and decreased Wnt signaling. Our findings reveal, for the first time, that CL metabolism regulates muscle differentiation through MyoD1 and identify the mechanism whereby MyoD1 is repressed in CL-deficient cells.
Collapse
Affiliation(s)
- Linh Vo
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Michael W Schmidtke
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | | | - Mindong Ren
- Department of Anesthesiology, Perioperative Care, and Pain Medicine at New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology at New York University Grossman School of Medicine, New York, New York, USA
| | - Michael Schlame
- Department of Anesthesiology, Perioperative Care, and Pain Medicine at New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology at New York University Grossman School of Medicine, New York, New York, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA.
| |
Collapse
|
3
|
Satthenapalli R, Lee S, Bellae Papannarao J, Hore TA, Chakraborty A, Jones PP, Lamberts RR, Katare R. Stage-specific regulation of signalling pathways to differentiate pluripotent stem cells to cardiomyocytes with ventricular lineage. Stem Cell Res Ther 2022; 13:185. [PMID: 35524336 PMCID: PMC9077927 DOI: 10.1186/s13287-022-02845-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/11/2022] [Indexed: 11/18/2022] Open
Abstract
Background Pluripotent stem cells (PSCs) can be an ideal source of differentiation of cardiomyocytes in vitro and during transplantation to induce cardiac regeneration. However, differentiation of PSCs into a heterogeneous population is associated with an increased incidence of arrhythmia following transplantation. We aimed to design a protocol to drive PSCs to a ventricular lineage by regulating Wnt and retinoic acid (RA) signalling pathways. Methods Mouse embryonic stem cells were cultured either in monolayers or three-dimensional hanging drop method to form embryonic bodies (EBs) and exposed to different treatments acting on Wnt and retinoic acid signalling. Samples were collected at different time points to analyse cardiomyocyte-specific markers by RT-PCR, flow cytometry and immunofluorescence. Results Treatment of monolayer and EBs with Wnt and RA signalling pathways and ascorbic acid, as a cardiac programming enhancer, resulted in the formation of an immature non-contractile cardiac population that expressed many of the putative markers of cardiac differentiation. The population exhibited upregulation of ventricular specific markers while suppressing the expression of pro-atrial and pro-sinoatrial markers. Differentiation of EBs resulted in early foetal like non-contractile ventricular cardiomyocytes with an inherent propensity to contract when stimulated. Conclusion Our results provide the first evidence of in vitro differentiation that mimics the embryonic morphogenesis towards ventricular specific cardiomyocytes through regulation of Wnt and RA signalling pathways. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-022-02845-9.
Collapse
Affiliation(s)
- Ramakanth Satthenapalli
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, 270, Great King Street, Dunedin, 9010, New Zealand
| | - Scott Lee
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, 270, Great King Street, Dunedin, 9010, New Zealand
| | - Jayanthi Bellae Papannarao
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, 270, Great King Street, Dunedin, 9010, New Zealand
| | - Timothy A Hore
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, 9010, New Zealand
| | - Akash Chakraborty
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, 270, Great King Street, Dunedin, 9010, New Zealand.,Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Peter P Jones
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, 270, Great King Street, Dunedin, 9010, New Zealand
| | - Regis R Lamberts
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, 270, Great King Street, Dunedin, 9010, New Zealand
| | - Rajesh Katare
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, 270, Great King Street, Dunedin, 9010, New Zealand.
| |
Collapse
|
4
|
Yao Y, Marra AN, Yelon D. Pathways Regulating Establishment and Maintenance of Cardiac Chamber Identity in Zebrafish. J Cardiovasc Dev Dis 2021; 8:13. [PMID: 33572830 PMCID: PMC7912383 DOI: 10.3390/jcdd8020013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 02/07/2023] Open
Abstract
The vertebrate heart is comprised of two types of chambers-ventricles and atria-that have unique morphological and physiological properties. Effective cardiac function depends upon the distinct characteristics of ventricular and atrial cardiomyocytes, raising interest in the genetic pathways that regulate chamber-specific traits. Chamber identity seems to be specified in the early embryo by signals that establish ventricular and atrial progenitor populations and trigger distinct differentiation pathways. Intriguingly, chamber-specific features appear to require active reinforcement, even after myocardial differentiation is underway, suggesting plasticity of chamber identity within the developing heart. Here, we review the utility of the zebrafish as a model organism for studying the mechanisms that establish and maintain cardiac chamber identity. By combining genetic and embryological approaches, work in zebrafish has revealed multiple players with potent influences on chamber fate specification and commitment. Going forward, analysis of cardiomyocyte identity at the single-cell level is likely to yield a high-resolution understanding of the pathways that link the relevant players together, and these insights will have the potential to inform future strategies in cardiac tissue engineering.
Collapse
Affiliation(s)
| | | | - Deborah Yelon
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; (Y.Y.); (A.N.M.)
| |
Collapse
|
5
|
Barisón MJ, Pereira IT, Waloski Robert A, Dallagiovanna B. Reorganization of Metabolism during Cardiomyogenesis Implies Time-Specific Signaling Pathway Regulation. Int J Mol Sci 2021; 22:1330. [PMID: 33572750 PMCID: PMC7869011 DOI: 10.3390/ijms22031330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 11/17/2022] Open
Abstract
Understanding the cell differentiation process involves the characterization of signaling and regulatory pathways. The coordinated action involved in multilevel regulation determines the commitment of stem cells and their differentiation into a specific cell lineage. Cellular metabolism plays a relevant role in modulating the expression of genes, which act as sensors of the extra-and intracellular environment. In this work, we analyzed mRNAs associated with polysomes by focusing on the expression profile of metabolism-related genes during the cardiac differentiation of human embryonic stem cells (hESCs). We compared different time points during cardiac differentiation (pluripotency, embryoid body aggregation, cardiac mesoderm, cardiac progenitor and cardiomyocyte) and showed the immature cell profile of energy metabolism. Highly regulated canonical pathways are thoroughly discussed, such as those involved in metabolic signaling and lipid homeostasis. We reveal the critical relevance of retinoic X receptor (RXR) heterodimers in upstream retinoic acid metabolism and their relationship with thyroid hormone signaling. Additionally, we highlight the importance of lipid homeostasis and extracellular matrix component biosynthesis during cardiomyogenesis, providing new insights into how hESCs reorganize their metabolism during in vitro cardiac differentiation.
Collapse
Affiliation(s)
| | | | | | - Bruno Dallagiovanna
- Basic Stem Cell Biology Laboratory, Instituto Carlos Chagas-FIOCRUZ-PR, Rua Professor Algacyr Munhoz Mader, 3775, Curitiba, PR 81350-010, Brazil; (M.J.B.); (I.T.P.); (A.W.R.)
| |
Collapse
|
6
|
Chakma K, Gu Z, Abudurexiti Y, Hata T, Motoi F, Unno M, Horii A, Fukushige S. Epigenetic inactivation of IRX4 is responsible for acceleration of cell growth in human pancreatic cancer. Cancer Sci 2020; 111:4594-4604. [PMID: 32894817 PMCID: PMC7734003 DOI: 10.1111/cas.14644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/29/2020] [Accepted: 09/01/2020] [Indexed: 12/19/2022] Open
Abstract
Epigenetic gene silencing by aberrant DNA methylation is one of the important mechanisms leading to loss of key cellular pathways in tumorigenesis. Methyl-CpG-targeted transcriptional activation (MeTA) reactivates hypermethylation-mediated silenced genes in a different way from DNA-demethylating agents. Microarray coupled with MeTA (MeTA-array) identified seven commonly hypermethylation-mediated silenced genes in 12 pancreatic ductal adenocarcinoma (PDAC) cell lines. Among these, we focused on IRX4 (Iroquois homeobox 4) because IRX4 is located at chromosome 5p15.33 where PDAC susceptibility loci have been identified through genome-wide association study. IRX4 was greatly downregulated in all of the analyzed 12 PDAC cell lines by promoter hypermethylation. In addition, the IRX4 promoter region was found to be frequently and specifically hypermethylated in primary resected PDACs (18/28: 64%). Reexpression of IRX4 inhibited colony formation and proliferation in two PDAC cell lines, PK-1 and PK-9. In contrast, knockdown of IRX4 accelerated cell proliferation in an IRX4-expressing normal pancreatic ductal epithelial cell line, HPDE-1. Because IRX4 is a sequence-specific transcription factor, downstream molecules of IRX4 were pursued by microarray analyses utilizing tetracycline-mediated IRX4 inducible PK-1 and PK-9 cells; CRYAB, CD69, and IL32 were identified as IRX4 downstream candidate genes. Forced expression of these genes suppressed colony formation abilities for both PK-1 and PK-9. These results suggest that DNA methylation-mediated silencing of IRX4 contributes to pancreatic tumorigenesis through aberrant transcriptional regulation of several cancer-related genes.
Collapse
MESH Headings
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/metabolism
- Carcinoma, Pancreatic Ductal/pathology
- Cell Line, Tumor
- Cell Proliferation/genetics
- DNA Methylation
- Down-Regulation
- Gene Knockdown Techniques/methods
- Gene Silencing
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Humans
- Interleukins/genetics
- Interleukins/metabolism
- Lectins, C-Type/genetics
- Lectins, C-Type/metabolism
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Plasmids
- Protein Array Analysis
- Tumor Stem Cell Assay
- Up-Regulation
- alpha-Crystallin B Chain/genetics
- alpha-Crystallin B Chain/metabolism
- Pancreatic Neoplasms
Collapse
Affiliation(s)
- Kanchan Chakma
- Division of PathologyTohoku University School of MedicineSendaiJapan
- Present address:
Department of Biochemistry and Molecular BiologyUniversity of ChittagongChittagongBangladesh
| | - Zhaodi Gu
- Division of PathologyTohoku University School of MedicineSendaiJapan
| | | | - Tatsuo Hata
- Department of Gastroenterological SurgeryTohoku University School of MedicineSendaiJapan
| | - Fuyuhiko Motoi
- Department of Gastroenterological SurgeryTohoku University School of MedicineSendaiJapan
- Present address:
Department of Surgery IYamagata University Graduate School of Medical ScienceYamagataJapan
| | - Michiaki Unno
- Department of Gastroenterological SurgeryTohoku University School of MedicineSendaiJapan
| | - Akira Horii
- Division of PathologyTohoku University School of MedicineSendaiJapan
- Present address:
Saka General HospitalShiogamaJapan
| | - Shinichi Fukushige
- Division of PathologyTohoku University School of MedicineSendaiJapan
- Center for Regulatory Epigenome and DiseasesTohoku University School of MedicineSendaiJapan
| |
Collapse
|
7
|
Hu W, Xin Y, Zhang L, Hu J, Sun Y, Zhao Y. Iroquois Homeodomain transcription factors in ventricular conduction system and arrhythmia. Int J Med Sci 2018; 15:808-815. [PMID: 30008591 PMCID: PMC6036080 DOI: 10.7150/ijms.25140] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/29/2018] [Indexed: 02/05/2023] Open
Abstract
Iroquois homeobox genes, Irx, encode cardiac transcription factors, Irx1-6 in most mammals. These six transcription factors are expressed in different patterns mainly in the ventricular part of the heart. Existing researches show that Irx genes play key roles in the differentiation and development of ventricular conduction system and the establishment and maintenance of gradient expression of potassium channels, Kv4.2. Our main focus of this review is on the recent advances in the discovery of above-mentioned genes and the function of the encoding products, how Irx genes establish ventricular conduction system and regulate ventricular repolarization, how the individual and complementary functions can be verified to complement our cognition and leads to novel therapeutic approaches.
Collapse
Affiliation(s)
- Wenyu Hu
- Department of Cardiology, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Yanguo Xin
- Department of Cardiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Lin Zhang
- Department of Cardiology, Jinqiu Hosipital Of Liaoning Province, Shenyang, Liaoning110001, China
| | - Jian Hu
- Department of Cardiology, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Yingxian Sun
- Department of Cardiology, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Yinan Zhao
- Department of Neurology, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, China
| |
Collapse
|
8
|
Ban K, Bae S, Yoon YS. Current Strategies and Challenges for Purification of Cardiomyocytes Derived from Human Pluripotent Stem Cells. Theranostics 2017. [PMID: 28638487 PMCID: PMC5479288 DOI: 10.7150/thno.19427] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Cardiomyocytes (CMs) derived from human pluripotent stem cells (hPSCs) are considered a most promising option for cell-based cardiac repair. Hence, various protocols have been developed for differentiating hPSCs into CMs. Despite remarkable improvement in the generation of hPSC-CMs, without purification, these protocols can only generate mixed cell populations including undifferentiated hPSCs or non-CMs, which may elicit adverse outcomes. Therefore, one of the major challenges for clinical use of hPSC-CMs is the development of efficient isolation techniques that allow enrichment of hPSC-CMs. In this review, we will discuss diverse strategies that have been developed to enrich hPSC-CMs. We will describe major characteristics of individual hPSC-CM purification methods including their scientific principles, advantages, limitations, and needed improvements. Development of a comprehensive system which can enrich hPSC-CMs will be ultimately useful for cell therapy for diseased hearts, human cardiac disease modeling, cardiac toxicity screening, and cardiac tissue engineering.
Collapse
|
9
|
Stefanovic S, Zaffran S. Mechanisms of retinoic acid signaling during cardiogenesis. Mech Dev 2016; 143:9-19. [PMID: 28007475 DOI: 10.1016/j.mod.2016.12.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 11/29/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
Abstract
Substantial experimental and epidemiological data have highlighted the interplay between nutritional and genetic factors in the development of congenital heart defects. Retinoic acid (RA), a derivative of vitamin A, plays a key role during vertebrate development including the formation of the heart. Retinoids bind to RA and retinoid X receptors (RARs and RXRs) which then regulate tissue-specific genes. Here, we will focus on the roles of RA signaling and receptors in gene regulation during cardiogenesis, and the consequence of deregulated retinoid signaling on heart formation and congenital heart defects.
Collapse
|
10
|
Ban K, Wile B, Cho KW, Kim S, Song MK, Kim SY, Singer J, Syed A, Yu SP, Wagner M, Bao G, Yoon YS. Non-genetic Purification of Ventricular Cardiomyocytes from Differentiating Embryonic Stem Cells through Molecular Beacons Targeting IRX-4. Stem Cell Reports 2016; 5:1239-1249. [PMID: 26651608 PMCID: PMC4682289 DOI: 10.1016/j.stemcr.2015.10.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Revised: 10/29/2015] [Accepted: 10/30/2015] [Indexed: 12/15/2022] Open
Abstract
Isolation of ventricular cardiomyocytes (vCMs) has been challenging due to the lack of specific surface markers. Here we show that vCMs can be purified from differentiating mouse embryonic stem cells (mESCs) using molecular beacons (MBs) targeting specific intracellular mRNAs. We designed MBs (IRX4 MBs) to target mRNA encoding Iroquois homeobox protein 4 (Irx4), a transcription factor specific for vCMs. To purify mESC vCMs, IRX4 MBs were delivered into cardiomyogenically differentiating mESCs, and IRX4 MBs-positive cells were FACS-sorted. We found that, of the cells isolated, ∼98% displayed vCM-like action potentials by electrophysiological analyses. These MB-purified vCMs continuously maintained their CM characteristics as verified by spontaneous beating, Ca2+ transient, and expression of vCM-specific proteins. Our study shows the feasibility of isolating pure vCMs via cell sorting without modifying host genes. The homogeneous and functional ventricular CMs generated via the MB-based method can be useful for disease investigation, drug discovery, and cell-based therapies. Molecular beacon (MB)-based method was developed to purify ventricular CMs from ESCs Ventricular CM-specific MBs targeting Irx4 mRNA were successfully generated About 98% of the CMs sorted via Irx4-MB displayed ventricular CM-like phenotypes Irx4-MB-based purified CMs continuously maintained ventricular CM characteristics
Collapse
Affiliation(s)
- Kiwon Ban
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Brian Wile
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA
| | - Kyu-Won Cho
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Sangsung Kim
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ming-Ke Song
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Sang Yoon Kim
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jason Singer
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Anum Syed
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA
| | - Shan Ping Yu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Mary Wagner
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Gang Bao
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA.
| | - Young-Sup Yoon
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA; Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 120-752, Korea.
| |
Collapse
|
11
|
Anderson C, Khan MAF, Wong F, Solovieva T, Oliveira NMM, Baldock RA, Tickle C, Burt DW, Stern CD. A strategy to discover new organizers identifies a putative heart organizer. Nat Commun 2016; 7:12656. [PMID: 27557800 DOI: 10.1038/ncomms12656] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/19/2016] [Indexed: 11/09/2022] Open
Abstract
Organizers are regions of the embryo that can both induce new fates and impart pattern on other regions. So far, surprisingly few organizers have been discovered, considering the number of patterned tissue types generated during development. This may be because their discovery has relied on transplantation and ablation experiments. Here we describe a new approach, using chick embryos, to discover organizers based on a common gene expression signature, and use it to uncover the anterior intestinal portal (AIP) endoderm as a putative heart organizer. We show that the AIP can induce cardiac identity from non-cardiac mesoderm and that it can pattern this by specifying ventricular and suppressing atrial regional identity. We also uncover some of the signals responsible. The method holds promise as a tool to discover other novel organizers acting during development.
Collapse
Affiliation(s)
- Claire Anderson
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Mohsin A F Khan
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Frances Wong
- Department of Genomics and Genetics, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG Scotland, UK
| | - Tatiana Solovieva
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Nidia M M Oliveira
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Richard A Baldock
- Biomedical Systems Analysis Section, MRC Human Genetics Unit, IGMM, University of Edinburgh, Crewe Road, Edinburgh, EH4 2XU, UK
| | - Cheryll Tickle
- Department of Biology &Biochemistry, University of Bath, Bath BA2 7AY, UK
| | - Dave W Burt
- Department of Genomics and Genetics, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG Scotland, UK
| | - Claudio D Stern
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| |
Collapse
|
12
|
Bloomekatz J, Galvez-Santisteban M, Chi NC. Myocardial plasticity: cardiac development, regeneration and disease. Curr Opin Genet Dev 2016; 40:120-130. [PMID: 27498024 DOI: 10.1016/j.gde.2016.05.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 05/29/2016] [Indexed: 01/14/2023]
Abstract
The adult mammalian heart is unable to recover from myocardial cell loss due to cardiac ischemia and infarction because terminally differentiated cardiomyocytes proliferate at a low rate. However, cardiomyocytes in other vertebrate animal models such as zebrafish, axolotls, newts and mammalian mouse neonates are capable of de-differentiating in order to promote cardiomyocyte proliferation and subsequent cardiac regeneration after injury. Although de-differentiation may occur in adult mammalian cardiomyocytes, it is typically associated with diseased hearts and pathologic remodeling rather than repair and regeneration. Here, we review recent studies of cardiac development, regeneration and disease that highlight how changes in myocardial identity (plasticity) is regulated and impacts adaptive and maladaptive cardiac responses.
Collapse
Affiliation(s)
- Joshua Bloomekatz
- Department of Medicine, Division of Cardiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Manuel Galvez-Santisteban
- Department of Medicine, Division of Cardiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Neil C Chi
- Department of Medicine, Division of Cardiology, University of California, San Diego, La Jolla, CA 92093, USA; Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
13
|
Liu D, Pattabiraman V, Bacanamwo M, Anderson LM. Iroquois homeobox transcription factor (Irx5) promotes G1/S-phase transition in vascular smooth muscle cells by CDK2-dependent activation. Am J Physiol Cell Physiol 2016; 311:C179-89. [PMID: 27170637 PMCID: PMC5129766 DOI: 10.1152/ajpcell.00293.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 05/06/2016] [Indexed: 12/30/2022]
Abstract
The Iroquois homeobox (Irx5) gene is essential in embryonic development and cardiac electrophysiology. Although recent studies have reported that IRX5 protein is involved in regulation of the cell cycle and apoptosis in prostate cancer cells, little is known about the role of IRX5 in the adult vasculature. Here we report novel observations on the role of IRX5 in adult vascular smooth muscle cells (VSMCs) during proliferation in vitro and in vivo. Comparative studies using primary human endothelial cells, VSMCs, and intact carotid arteries to determine relative expression of Irx5 in the peripheral vasculature demonstrate significantly higher expression in VSMCs. Sprague-Dawley rat carotid arteries were subjected to balloon catherization, and the presence of IRX5 was examined by immunohistochemistry after 2 wk. Results indicate markedly elevated IRX5 signal at 14 days compared with uninjured controls. Total RNA was isolated from injured and uninjured arteries, and Irx5 expression was measured by RT-PCR. Results demonstrate a significant increase in Irx5 expression at 3-14 days postinjury compared with controls. Irx5 genetic gain- and loss-of-function studies using thymidine and 5-bromo-2'-deoxyuridine incorporation assays resulted in modulation of DNA synthesis in primary rat aortic VSMCs. Quantitative RT-PCR results revealed modulation of cyclin-dependent kinase inhibitor 1B (p27(kip1)), E2F transcription factor 1 (E2f1), and proliferating cell nuclear antigen (Pcna) expression in Irx5-transduced VSMCs compared with controls. Subsequently, apoptosis was observed and confirmed by morphological observation, caspase-3 cleavage, and enzymatic activation compared with control conditions. Taken together, these results indicate that Irx5 plays an important role in VSMC G1/S-phase cell cycle checkpoint control and apoptosis.
Collapse
Affiliation(s)
- Dong Liu
- Cardiovascular Research Institute, Morehouse School of Medicine, Atlanta, Georgia; Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia; and
| | - Vaishnavi Pattabiraman
- Cardiovascular Research Institute, Morehouse School of Medicine, Atlanta, Georgia; Department of Medicine, Morehouse School of Medicine, Atlanta, Georgia
| | - Methode Bacanamwo
- Cardiovascular Research Institute, Morehouse School of Medicine, Atlanta, Georgia; Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia; and
| | - Leonard M Anderson
- Cardiovascular Research Institute, Morehouse School of Medicine, Atlanta, Georgia; Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia; and
| |
Collapse
|
14
|
Diez ER, Altamirano LB, García IM, Mazzei L, Prado NJ, Fornes MW, Carrión FDC, Zumino AZP, Ferder L, Manucha W. Heart remodeling and ischemia-reperfusion arrhythmias linked to myocardial vitamin d receptors deficiency in obstructive nephropathy are reversed by paricalcitol. J Cardiovasc Pharmacol Ther 2014; 20:211-20. [PMID: 24924917 DOI: 10.1177/1074248414538704] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Cardiovascular disease is often associated with chronic kidney disease and vice versa; myocardial vitamin D receptors (VDRs) are among the probable links between the 2 disorders. The vitamin D receptor activator paricalcitol protects against some renal and cardiovascular complications. However, the structural and electrophysiological effects of myocardial vitamin D receptor modification and its impact on the response to ischemia-reperfusion are currently unknown. This work attempted to determine whether obstructive nephropathy induced myocardial changes (in rats) linked to vitamin D receptor deficiency and to ventricular arrhythmias in Langendorff-perfused hearts. Unilateral ureteral-obstructed and Sham-operated rats were treated with either paricalcitol (30 ng/kg/d intraperitoneal) or vehicle for 15 days. In 5 hearts from each group, we found that obstructed rats showed a reduction in VDRs and an increase in angiotensin II type 1 receptor expression (messenger RNA and protein), suffered fibrosis (determined by Masson trichrome stain) and myofibril reduction with an increase in mitochondrial size, and had dilated crests (determined by electron microscopy). These changes were reversed by paricalcitol. In 8 additional hearts per group, we found that obstructed rats showed a higher incidence of ventricular fibrillation during reperfusion (after 10 minutes of regional ischemia) than did those treated with paricalcitol. The action potential duration was prolonged throughout the experiment in paricalcitol-treated rats. We conclude that the reduction in myocardial vitamin D receptor expression in obstructed rats might be related to myocardial remodeling associated with an increase in arrhythmogenesis and that paricalcitol protects against these changes by restoring myocardial vitamin D receptor levels and prolonging action potentials.
Collapse
Affiliation(s)
- Emiliano Raúl Diez
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina
| | - Liliana Berta Altamirano
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina Pathology Department, Medical Sciences College, National University of Cuyo, Mendoza, Argentina
| | - Isabel Mercedes García
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina
| | - Luciana Mazzei
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina
| | - Natalia Jorgelina Prado
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina
| | - Miguel Walter Fornes
- Institute of Histology and Embryology of Mendoza, National Scientific and Technical Research Council, Mendoza, Argentina
| | - Fernando Darío Cuello Carrión
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina
| | - Amira Zulma Ponce Zumino
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina
| | - León Ferder
- Department of Physiology and Pharmacology, Ponce School of Medicine and Health Sciences, Ponce, Puerto Rico
| | - Walter Manucha
- Institute of Medical and Experimental Biology of Cuyo, National Scientific and Technical Research Council, Mendoza, Argentina Pathology Department, Medical Sciences College, National University of Cuyo, Mendoza, Argentina
| |
Collapse
|
15
|
Chuang HN, Hsiao KM, Chang HY, Wu CC, Pan H. The homeobox transcription factor Irxl1 negatively regulates MyoD expression and myoblast differentiation. FEBS J 2014; 281:2990-3003. [PMID: 24814716 DOI: 10.1111/febs.12837] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/07/2014] [Accepted: 04/30/2014] [Indexed: 11/29/2022]
Abstract
Irxl1/Mkx (Iroquois homeobox-like 1/Mohawk) encodes a member of the TALE subfamily of homeodomain proteins. It is expressed in multiple mesoderm-derived tissues and has recently been shown to regulate tendon differentiation during mouse embryonic development. Previously we showed that knockdown of Irxl1 in zebrafish caused a deficit in neural crest cells which consequently resulted in deformation of craniofacial muscles and arch cartilages. Here, we further demonstrate that loss of Irxl1 function results in deformed somites with disordered muscle fibers and myotendinous junctions. Because expression of myoD is increased in the somites of Irxl1 knockdown morphants, we test whether Irxl1 negatively regulates myoD expression. When stable C2C12 myoblasts overexpressing Irxl1/Mkx were induced to differentiate, myotube formation was inhibited and protein levels of myoD and myosin heavy chain were decreased accordingly. A series of deletion constructs of myoD promoter fragments were tested by luciferase reporter assays, which identified a promoter fragment that is necessary and sufficient for Irxl1-mediated repression. Direct interaction of Irxl1 and myoD promoter was subsequently elucidated by yeast one-hybrid assays, electrophoretic mobility shift assays and chromatin immunoprecipitation analysis. Furthermore, mouse Mkx also binds to and represses myoD promoter. These results indicate that Irxl1/Mkx can repress myoD expression through direct binding to its promoter and may thus play a negative regulatory role in muscle differentiation.
Collapse
Affiliation(s)
- Han-Ni Chuang
- Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi, Taiwan; Department of Biomedical Sciences, Chung Shan Medical University, Taichung, Taiwan
| | | | | | | | | |
Collapse
|
16
|
Abstract
Vitamin D receptors (VDR) are found in cells throughout the cardiovascular system. A variety of experimental studies indicate that the liganded VDR may play an important role in controlling cardiac hypertrophy and fibrosis, regulating blood pressure, and suppressing the development of atherosclerosis. Some, but not all, observational studies in humans provide support for these experimental findings, raising the possibility that vitamin D or its analogs might prove useful therapeutically in the prevention or treatment of cardiovascular disease.
Collapse
Affiliation(s)
- David G Gardner
- Diabetes Center, University of California at San Francisco, San Francisco, California; and
| | | | | |
Collapse
|
17
|
Kostareli E, Holzinger D, Bogatyrova O, Hielscher T, Wichmann G, Keck M, Lahrmann B, Grabe N, Flechtenmacher C, Schmidt CR, Seiwert T, Dyckhoff G, Dietz A, Höfler D, Pawlita M, Benner A, Bosch FX, Plinkert P, Plass C, Weichenhan D, Hess J. HPV-related methylation signature predicts survival in oropharyngeal squamous cell carcinomas. J Clin Invest 2013; 123:2488-501. [PMID: 23635773 DOI: 10.1172/jci67010] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 02/22/2013] [Indexed: 01/30/2023] Open
Abstract
High-risk types of human papilloma virus (HPV) are increasingly associated with oropharyngeal squamous cell carcinoma (OPSCC). Strikingly, patients with HPV-positive OPSCC are highly curable with ionizing radiation and have better survival compared with HPV-negative patients, but the underlying molecular mechanisms remain poorly understood. We applied an array-based approach to monitor global changes in CpG island hypermethylation between HPV-negative and HPV-positive OPSCCs and identified a specific pattern of differentially methylated regions that critically depends on the presence of viral transcripts. HPV-related alterations were confirmed for the majority of candidate gene promoters by mass spectrometric, quantitative methylation analysis. There was a significant inverse correlation between promoter hypermethylation of ALDH1A2, OSR2, GATA4, GRIA4, and IRX4 and transcript levels. Interestingly, Kaplan-Meier analysis revealed that a combined promoter methylation pattern of low methylation levels in ALDH1A2 and OSR2 promoters and high methylation levels in GATA4, GRIA4, and IRX4 promoters was significantly correlated with improved survival in 3 independent patient cohorts. ALDH1A2 protein levels, determined by immunohistochemistry on tissue microarrays, confirmed the association with clinical outcome. In summary, our study highlights specific alterations in global gene promoter methylation in HPV-driven OPSCCs and identifies a signature that predicts the clinical outcome in OPSCCs.
Collapse
Affiliation(s)
- Efterpi Kostareli
- Department of Otolaryngology, Head and Neck Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Kim KH, Rosen A, Bruneau BG, Hui CC, Backx PH. Iroquois homeodomain transcription factors in heart development and function. Circ Res 2012; 110:1513-24. [PMID: 22628575 DOI: 10.1161/circresaha.112.265041] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Numerous cardiac transcription factors play overlapping roles in both the specification and proliferation of the cardiac tissues and chambers during heart development. It has become increasingly apparent that cardiac transcription factors also play critical roles in the regulation of expression of many functional genes in the prenatal and postnatal hearts. Accordingly, mutations of cardiac transcription factors cannot only result in congenital heart defects but also alter heart function thereby predisposing to heart disease and cardiac arrhythmias. In this review, we summarize the roles of Iroquois homeobox (Irx) family of transcription factors in heart development and function. In all, 6 Irx genes are expressed with distinct and overlapping patterns in the mammalian heart. Studies in several animal models demonstrate that Irx genes are important for the establishment of ventricular chamber properties, the ventricular conduction system, as well as heterogeneity of the ventricular repolarization. The molecular mechanisms by which Irx proteins regulate gene expression and the clinical relevance of Irx functions in the heart are discussed.
Collapse
Affiliation(s)
- Kyoung-Han Kim
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | |
Collapse
|
19
|
The absence of dystrophin brain isoform expression in healthy human heart ventricles explains the pathogenesis of 5' X-linked dilated cardiomyopathy. BMC MEDICAL GENETICS 2012; 13:20. [PMID: 22455600 PMCID: PMC3331845 DOI: 10.1186/1471-2350-13-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 03/28/2012] [Indexed: 12/11/2022]
Abstract
BACKGROUND In X-linked dilated cardiomyopathy due to dystrophin mutations which abolish the expression of the M isoform (5'-XLDC), the skeletal muscle is spared through the up-regulation of the Brain (B) isoform, a compensatory mechanism that does not appear to occur in the heart of affected individuals. METHODS We quantitatively studied the expression topography of both B and M isoforms in various human heart regions through in-situ RNA hybridization, Reverse-Transcriptase and Real-Time PCR experiments. We also investigated the methylation profile of the B promoter region in the heart and quantified the B isoform up regulation in the skeletal muscle of two 5'-XLDC patients. RESULTS Unlike the M isoform, consistently detectable in all the heart regions, the B isoform was selectively expressed in atrial cardiomyocytes, but absent in ventricles and in conduction system structures. Although the level of B isoform messenger in the skeletal muscle of 5'-XLDC patients was lower that of the M messenger present in control muscle, it seems sufficient to avoid an overt muscle pathology. This result is consistent with the protein level in XLDC patients muscles we previously quantified. Methylation studies revealed that the B promoter shows an overall low level of methylation at the CG dinucleotides in both atria and ventricles, suggesting a methylation-independent regulation of the B promoter activity. CONCLUSIONS The ventricular dilatation seen in 5'-XLDC patients appears to be functionally related to loss of the M isoform, the only isoform transcribed in human ventricles; in contrast, the B isoform is well expressed in heart but confined to the atria. Since the B isoform can functionally replace the M isoform in the skeletal muscle, its expression in the heart could potentially exert the same rescue function. Methylation status does not seem to play a role in the differential B promoter activity in atria and ventricles, which may be governed by other regulatory mechanisms. If these mechanisms could be deduced, de-silencing of the B isoform may represent a therapeutic strategy in 5'-XLDC patients.
Collapse
|
20
|
Nguyen HH, Takata R, Akamatsu S, Shigemizu D, Tsunoda T, Furihata M, Takahashi A, Kubo M, Kamatani N, Ogawa O, Fujioka T, Nakamura Y, Nakagawa H. IRX4 at 5p15 suppresses prostate cancer growth through the interaction with vitamin D receptor, conferring prostate cancer susceptibility. Hum Mol Genet 2012; 21:2076-85. [PMID: 22323358 DOI: 10.1093/hmg/dds025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Recent genome-wide association studies (GWAS) identified a number of prostate cancer (PC) susceptibility loci, but most of their functional significances are not elucidated. Through our previous GWAS for PC in a Japanese population and subsequent resequencing and fine mapping, we here identified that IRX4 (Iroquois homeobox 4), coding Iroquois homeobox 4, is a causative gene of the PC susceptibility locus (rs12653946) at chromosome 5p15. IRX4 is expressed specifically in the prostate and heart, and quantitative expression analysis revealed a significant association between the genotype of rs12653946 and IRX4 expression in normal prostate tissues. Knockdown of IRX4 in PC cells enhanced their growth and IRX4 overexpression in PC cells suppressed their growth, indicating the functional association of IRX4 with PC and its tumor suppressive effect. Immunoprecipitation confirmed its protein-protein interaction to vitamin D receptor (VDR), and we found a significant interaction between IRX4 and VDR in their reciprocal transcriptional regulation. These findings indicate that the PC-susceptibility locus represented by rs12653946 at 5p15 is likely to regulate IRX4 expression in prostate which could suppress PC growth by interacting with the VDR pathway, conferring to PC susceptibility.
Collapse
Affiliation(s)
- Hai Ha Nguyen
- Laboratory for Biomarker Development, Center for Genome Medicine, RIKEN, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Affiliation(s)
- Robert G. Kelly
- From the Developmental Biology Institute of Marseilles-Luminy, Université de la Méditerranée, Marseilles, France
| |
Collapse
|
22
|
Cheng Z, Wang J, Su D, Pan H, Huang G, Li X, Li Z, Shen A, Xie X, Wang B, Ma X. Two novel mutations of the IRX4 gene in patients with congenital heart disease. Hum Genet 2011; 130:657-62. [PMID: 21544582 DOI: 10.1007/s00439-011-0996-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 04/19/2011] [Indexed: 11/24/2022]
Abstract
IRX4 was the first identified cardiac transcription factor that is restricted to the ventricles at all stages of heart development. Irx4-deficient mice show ventricular dysfunction and develop cardiomyopathy. To study the potential impact of sequence variations in IRX4 on congenital heart disease (CHD) in humans, we examined the coding region of IRX4 in a cohort of 698 Chinese people with congenital heart disease and 250 healthy individuals as the controls. We found two potential disease-causing mutations, p. Asn85Tyr and p. Glu92Gly. A mammalian two-hybrid assay showed that both of the mutations significantly affected the interaction between IRX4 and RXRA. It demonstrated that IRX4 had a potential causative impact on the development of congenital heart disease, particularly ventricular septal defect.
Collapse
Affiliation(s)
- Zhi Cheng
- Graduate School, Peking Union Medical College, Beijing, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
The myocardium of the heart is composed of multiple highly specialized myocardial lineages, including those of the ventricular and atrial myocardium, and the specialized conduction system. Specification and maturation of each of these lineages during heart development is a highly ordered, ongoing process involving multiple signaling pathways and their intersection with transcriptional regulatory networks. Here, we attempt to summarize and compare much of what we know about specification and maturation of myocardial lineages from studies in several different vertebrate model systems. To date, most research has focused on early specification, and although there is still more to learn about early specification, less is known about factors that promote subsequent maturation of myocardial lineages required to build the functioning adult heart.
Collapse
Affiliation(s)
- Sylvia M Evans
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla CA 92093, USA.
| | | | | | | |
Collapse
|
24
|
Doi T, Lukošiūtė A, Ruttenstock E, Dingemann J, Puri P. Expression of Iroquois genes is up-regulated during early lung development in the nitrofen-induced pulmonary hypoplasia. J Pediatr Surg 2011; 46:62-6. [PMID: 21238641 DOI: 10.1016/j.jpedsurg.2010.09.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 09/30/2010] [Indexed: 11/17/2022]
Abstract
BACKGROUND/PURPOSE Iroquois homeobox (Irx) genes have been implicated in the early lung morphogenesis of vertebrates. Irx1-3 and Irx5 gene expression is seen in fetal lung in rodents up to day (D) 18.5 of gestation. Fetal lung in Irx knockdown mice shows loss of mesenchyme and dilated airspaces, whereas nitrofen-induced hypoplastic lung displays thickened mesenchyme and diminished airspaces. We hypothesized that the Irx genes are up-regulated during early lung morphogenesis in the nitrofen-induced hypoplastic lung. METHODS Pregnant rats were exposed either to olive oil or nitrofen on D9. Fetal lungs harvested on D15 were divided into control and nitrofen groups; and the lungs harvested on D18 were divided into control, nitrofen without congenital diaphragmatic hernia (CDH[-]), and nitrofen with CDH (CDH[+]). Irx gene expression levels were analyzed by reverse transcriptase polymerase chain reaction. Immunohistochemistry was performed to evaluate protein expression of Irx family. RESULTS Pulmonary Irx1-3 and Irx5 messenger RNA expression levels were significantly up-regulated in nitrofen group compared with controls at D15. On D15, Irx immunoreactivity was increased in nitrofen-induced hypoplastic lung compared with controls. CONCLUSION Overexpression of Irx genes in the early lung development may cause pulmonary hypoplasia in the nitrofen CDH model by inducing lung dysmorphogenesis with thickened mesenchyme and diminished airspaces.
Collapse
Affiliation(s)
- Takashi Doi
- National Children's Research Centre, Our Lady's Children's Hospital, Dublin, Ireland
| | | | | | | | | |
Collapse
|
25
|
Pilz S, Tomaschitz A, Drechsler C, Dekker JM, März W. Vitamin D deficiency and myocardial diseases. Mol Nutr Food Res 2010; 54:1103-13. [PMID: 20352623 DOI: 10.1002/mnfr.200900474] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vitamin D deficiency is common among patients with myocardial diseases because sun-induced vitamin D production in the skin and dietary intake of vitamin D is often insufficient. Knockout mice for the vitamin D receptor develop myocardial hypertrophy and dysfunction. It has also been shown that children with rickets who suffered from severe heart failure could be successfully treated with supplementation of vitamin D plus calcium. In adults, almost all patients with heart failure exhibit reduced 25-hydroxyvitamin D levels, which are used to classify the vitamin D status. In prospective studies, vitamin D deficiency was an independent risk factor for mortality, deaths due to heart failure and sudden cardiac death. Several vitamin D effects on the electrophysiology, contractility, and structure of the heart suggest that vitamin D deficiency might be a causal factor for myocardial diseases. Data from interventional trials, however, are rare and urgently needed to elucidate whether vitamin D supplementation is useful for the treatment of myocardial diseases. In our opinion, the current knowledge of the beneficial effects of vitamin D on myocardial and overall health strongly argue for vitamin D supplementation in all vitamin D-deficient patients with or at high risk for myocardial diseases.
Collapse
Affiliation(s)
- Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Graz, Austria.
| | | | | | | | | |
Collapse
|
26
|
Ng SY, Wong CK, Tsang SY. Differential gene expressions in atrial and ventricular myocytes: insights into the road of applying embryonic stem cell-derived cardiomyocytes for future therapies. Am J Physiol Cell Physiol 2010; 299:C1234-49. [PMID: 20844252 DOI: 10.1152/ajpcell.00402.2009] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myocardial infarction has been the leading cause of morbidity and mortality in developed countries over the past few decades. The transplantation of cardiomyocytes offers a potential method of treatment. However, cardiomyocytes are in high demand and their supply is extremely limited. Embryonic stem cells (ESCs), which have been isolated from the inner cell mass of blastocysts, can self-renew and are pluripotent, meaning they have the ability to develop into any type of cell, including cardiomyocytes. This suggests that ESCs could be a good source of genuine cardiomyocytes for future therapeutic purposes. However, problems with the yield and purity of ESC-derived cardiomyocytes, among other hurdles for the therapeutic application of ESC-derived cardiomyocytes (e.g., potential immunorejection and tumor formation problems), need to be overcome before these cells can be used effectively for cell replacement therapy. ESC-derived cardiomyocytes consist of nodal, atrial, and ventricular cardiomyocytes. Specifically, for treatment of myocardial infarction, transplantation of a sufficient quantity of ventricular cardiomyocytes, rather than nodal or atrial cardiomyocytes, is preferred. Hence, it is important to find ways of increasing the yield and purity of specific types of cardiomyocytes. Atrial and ventricular cardiomyocytes have differential expression of genes (transcription factors, structural proteins, ion channels, etc.) and are functionally distinct. This paper presents a thorough review of differential gene expression in atrial and ventricular myocytes, their expression throughout development, and their regulation. An understanding of the molecular and functional differences between atrial and ventricular myocytes allows discussion of potential strategies for preferentially directing ESCs to differentiate into chamber-specific cells, or for fine tuning the ESC-derived cardiomyocytes into specific electrical and contractile phenotypes resembling chamber-specific cells.
Collapse
Affiliation(s)
- Sze Ying Ng
- Biochemistry Programme, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | | | | |
Collapse
|
27
|
|
28
|
Zhang R, Xu X. Transient and transgenic analysis of the zebrafish ventricular myosin heavy chain (vmhc) promoter: an inhibitory mechanism of ventricle-specific gene expression. Dev Dyn 2009; 238:1564-73. [PMID: 19322764 PMCID: PMC2756512 DOI: 10.1002/dvdy.21929] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The zebrafish ventricular myosin heavy chain (vmhc) gene exhibits restricted expression in the ventricle. However, the molecular mechanism underlying this chamber-specific expression is unclear. Here, we exploited both transient and transgenic technologies to dissect the zebrafish vmhc promoter. We demonstrated that a combination of two transient assays in this animal model quickly identified chamber-specific cis-elements, isolating a 2.2 kb fragment upstream from the vmhc gene that can drive ventricle-specific expression. Furthermore, deletion analysis identified multiple cis-elements that exhibited cardiac-specific expression. To achieve chamber specificity, a distal element was required to coordinate with and suppress a proximal enhancer element. Finally, we discovered that Nkx2.5-binding sites (NKE) were essential for this repressive function. In summary, our study of the zebrafish vmhc promoter suggests that ventricle-specific expression is achieved through an inhibitory mechanism that suppresses expression in the atrium. Developmental Dynamics 238:1564-1573, 2009. (c) 2009 Wiley-Liss, Inc.
Collapse
Affiliation(s)
- Ruilin Zhang
- Department of Biochemistry and Molecular Biology/Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology/Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, Minnesota
| |
Collapse
|
29
|
He W, Jia Y, Takimoto K. Interaction between transcription factors Iroquois proteins 4 and 5 controls cardiac potassium channel Kv4.2 gene transcription. Cardiovasc Res 2008; 81:64-71. [PMID: 18815185 DOI: 10.1093/cvr/cvn259] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The homeobox transcription factor, Iroquois protein 5 (Irx5), plays an essential role in the generation of region-selective expression of Kv4.2 gene across the left ventricular wall of rodent hearts. Here, we analyse molecular mechanisms underlying the Irx5-induced regulation of the rat Kv4.2 promoter. METHODS AND RESULTS The mRNA levels for Irx members in various heart regions were assessed by RT-PCR. A luciferase reporter gene with the rat Kv4.2 promoter was used to test the effects of Irx members on channel promoter activity. Irx3 and Irx5 mRNAs were differentially distributed across the left ventricular wall, whereas Irx4 message was equally abundant in various ventricular regions. Irx5, but not Irx3 or Irx4, increased Kv4.2 promoter activity in 10T1/2 fibroblasts, whereas the transcription factor decreased promoter activity in neonatal ventricular myocytes. These effects were mediated by the C-terminal portion of Irx5. Irx4 appeared to inhibit the Irx5-induced increase in channel promoter activity in 10T1/2 cells. The N-terminal region of Irx4 was necessary and sufficient for this inhibition. Furthermore, when endogenous Irx4 expression was suppressed with siRNA, Irx5 increased channel promoter activity in neonatal myocytes. CONCLUSION These results indicate that Irx5 possesses the ability to activate the Kv4.2 promoter. The abundant Irx4 expression throughout the rat ventricle may play a role in the inverse relationship between Irx5 and Kv4.2 levels across the left ventricular wall.
Collapse
Affiliation(s)
- Wenjie He
- Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, 100 Technology Drive, Bridgeside Point, Pittsburgh, PA 15219, USA
| | | | | |
Collapse
|
30
|
Myrthue A, Rademacher BLS, Pittsenbarger J, Kutyba-Brooks B, Gantner M, Qian DZ, Beer TM. The iroquois homeobox gene 5 is regulated by 1,25-dihydroxyvitamin D3 in human prostate cancer and regulates apoptosis and the cell cycle in LNCaP prostate cancer cells. Clin Cancer Res 2008; 14:3562-70. [PMID: 18519790 DOI: 10.1158/1078-0432.ccr-07-4649] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
1,25-Dihydroxyvitamin D3 [1,25(OH)2D3], the most active metabolite of vitamin D3, has significant antitumor activity in a broad range of preclinical models of cancer. In this study, we show that the Iroquois homeobox gene 5 (Irx5) is down-regulated by 1,25(OH)2D3 in human prostate cancer samples from patients randomly assigned to receive weekly high-dose 1,25(OH)2D3 or placebo before radical prostatectomy. Down-regulation of Irx5 by 1,25(OH)2D3 was also shown in the human androgen-sensitive prostate cancer cell line LNCaP and in estrogen-sensitive MCF-7 breast cancer cells. Knockdown of Irx5 by RNA interference showed a significant reduction in LNCaP cell viability, which was accompanied by an increase in p21 protein expression, G2-M arrest, and an increase in apoptosis. The induced apoptosis was partially mediated by p53, and p53 protein expression was increased as a result of Irx5 knockdown. Cell survival was similarly reduced by Irx5 knockdown in the colon cancer cell line HCT 116 and in MCF-7 breast cancer cells, each being derived from clinical tumor types that seem to be inhibited by 1,25(OH)2D3. Overexpression of Irx5 led to a reduction of p21 and p53 expression. This is the first report that Irx5 is regulated by 1,25(OH)2D3 in humans and the first report to show that Irx5 is involved in the regulation of both the cell cycle and apoptosis in human prostate cancer cells. Irx5 may be a promising new therapeutic target in cancer treatment.
Collapse
Affiliation(s)
- Anne Myrthue
- Division of Hematology and Medical Oncology, Oregon Health and Science University, CH-14R, 3303 SW Bond Avenue, Portland, OR 97239, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Fryer RM, Rakestraw PA, Nakane M, Dixon D, Banfor PN, Koch KA, Wu-Wong JR, Reinhart GA. Differential Inhibition of Renin mRNA Expression by Paricalcitol and Calcitriol in C57/BL6 Mice. ACTA ACUST UNITED AC 2007; 106:p76-81. [PMID: 17622742 DOI: 10.1159/000104875] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2006] [Accepted: 04/26/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Vitamin D receptor activators (VDRAs) may suppress renin expression and VDR-mediated renin inhibitors may offer a novel mechanism to control the RAS. METHODS We delineated the effects of paricalcitol and calcitriol on PTH, renin, and iCa(2+) in C57/BL6 mice administered vehicle, paricalcitol, or calcitriol (0.01, 0.03, 0.10, 0.33, 1.0 microg/kg s.c.) 3 days/week for 9 days. RESULTS Paricalcitol produced PTH suppression from 0.03 to 1.0 microg/kg (values between 9.7 +/- 3.3 and 20.7 +/- 4.7 pg/ml; vehicle = 88.0 +/- 16.9) and elicited dose-dependent reductions in renin/GAPDH expression at 0.33 and 1.0 microg/kg (0.037 +/- 0.002, 0.027 +/- 0.003; vehicle = 0.054 +/- 0.003) but produced no increases iCa(2+) at any dose tested. Calcitrol produced PTH suppression at all doses tested (between 6.4 +/- 1.2 and 29.5 +/- 17.2 pg/ml) and renin suppression at 0.10, 0.33, and 1.0 microg/kg (0.029 +/- 0.002, 0.031 +/- 0.003, and 0.038 +/- 0.02). However, at 0.33 and 1.0 mg/kg, calcitriol produced increases iCa(2+) (1.31 +/- 0.03 and 1.48 +/- 0.02 mmol/l; vehicle = 1.23 +/- 0.02 mmol/l). CONCLUSIONS Paricalcitol produces significant, dose-dependent suppression of renin expression in the absence of hypercalcemia at doses 10-fold above those necessary for PTH suppression. Calcitriol also produced suppression of renin at doses at least 10-fold above those required for PTH suppression, but increases in iCa(2+) were observed at doses only 3-fold above those necessary to elicit renin suppression.
Collapse
Affiliation(s)
- Ryan M Fryer
- Integrative Pharmacology, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064-6119, USA.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Xin M, Small EM, van Rooij E, Qi X, Richardson JA, Srivastava D, Nakagawa O, Olson EN. Essential roles of the bHLH transcription factor Hrt2 in repression of atrial gene expression and maintenance of postnatal cardiac function. Proc Natl Acad Sci U S A 2007; 104:7975-80. [PMID: 17468400 PMCID: PMC1876557 DOI: 10.1073/pnas.0702447104] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The basic helix-loop-helix transcriptional repressor Hairy-related transcription factor 2 (Hrt2) is expressed in ventricular, but not atrial, cardiomyocytes, and in endothelial and vascular smooth muscle cells. Mice homozygous for a null mutation of Hrt2 die perinatally from a spectrum of cardiac abnormalities, raising questions about the specific functions of this transcriptional regulator in individual cardiac cell lineages. Using a conditional Hrt2 null allele, we show that cardiomyocyte-specific deletion of Hrt2 in mice results in ectopic activation of atrial genes in ventricular myocardium with an associated impairment of cardiac contractility and a unique distortion in morphology of the right ventricular chamber. Consistent with the atrialization of ventricular gene expression in Hrt2 mutant mice, forced expression of Hrt2 in atrial cardiomyocytes is sufficient to repress atrial cardiac genes. These findings reveal a ventricular myocardial cell-autonomous function for Hrt2 in the suppression of atrial cell identity and the maintenance of postnatal cardiac function.
Collapse
Affiliation(s)
- Mei Xin
- Departments of *Molecular Biology
| | | | | | | | - James A. Richardson
- Departments of *Molecular Biology
- Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390
| | - Deepak Srivastava
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158; and
- Departments of Pediatrics (Cardiology) and Biochemistry and Biophysics, University of California, San Francisco, CA 94143
| | | | - Eric N. Olson
- Departments of *Molecular Biology
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
33
|
Liu H, Liu W, Maltby KM, Lan Y, Jiang R. Identification and developmental expression analysis of a novel homeobox gene closely linked to the mouse Twirler mutation. Gene Expr Patterns 2006; 6:632-6. [PMID: 16426902 PMCID: PMC3869088 DOI: 10.1016/j.modgep.2005.11.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 11/11/2005] [Accepted: 11/21/2005] [Indexed: 10/25/2022]
Abstract
The Twirler mutation arose spontaneously and causes inner ear defects in heterozygous and cleft lip and/or cleft palate in homozygous mutant mice, providing a unique animal model for investigating the molecular mechanisms of inner ear and craniofacial development. Here, we report the identification of a novel homeobox gene, Iroquois-related homeobox like-1 (Irxl1), from the Twirler locus. Irxl1 encodes a TALE-family homeodomain protein with its homeodomain exhibiting the highest amino acid sequence identity (54%) to those of invertebrate Iroquois and vertebrate Irx subfamily members. The putative Irxl1 protein lacks the Iro-box, a conserved motif in all known members of the Irx subfamily. Searching the databases showed that Irxl1 orthologs exist in Xenopus, chick, and mammals. In situ hybridization analyses of mouse embryos at various developmental stages showed that Irxl1 mRNA is highly expressed in the frontonasal process and palatal mesenchyme during primary and secondary palate development. In addition, Irxl1 mRNA is strongly expressed in mesenchyme surrounding the developing inner ear, in discrete regions of the developing mandible, in the dermamyotome during somite differentiation, and in a subset of muscular structures in late embryonic stages. The developmental expression pattern indicates that Irxl1 is a good candidate gene for the Twirler gene.
Collapse
Affiliation(s)
- Han Liu
- Department of Biology, University of Rochester, Rochester, NY 14627
| | - Wenjin Liu
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
| | - Kathleen M. Maltby
- Center for Oral Biology and Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
| | - Yu Lan
- Center for Oral Biology and Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
| | - Rulang Jiang
- Department of Biology, University of Rochester, Rochester, NY 14627
- Center for Oral Biology and Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
- Author for Correspondence: Rulang Jiang, Ph.D, Center for Oral Biology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 611, Rochester, NY 14642, Telephone: (585)273-1426, Fax: (585)276-0190,
| |
Collapse
|
34
|
Smith SJ, Ataliotis P, Kotecha S, Towers N, Sparrow DB, Mohun TJ. The MLC1v gene provides a transgenic marker of myocardium formation within developing chambers of the Xenopus heart. Dev Dyn 2005; 232:1003-12. [PMID: 15736168 DOI: 10.1002/dvdy.20274] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many details of cardiac chamber morphogenesis could be revealed if muscle fiber development could be visualized directly within the hearts of living vertebrate embryos. To achieve this end, we have used the active promoter of the MLC1v gene to drive expression of green fluorescent protein (GFP) in the developing tadpole heart. By using a line of Xenopus laevis frogs transgenic for the MLC1v-EGFP reporter, we have observed regionalized patterns of muscle formation within the ventricular chamber and maturation of the atrial chambers, from the onset of chamber formation through to the adult frog. In f1 generation MLC1v-EGFP animals, promoter activity is first detected within the looping heart tube and delineates the forming ventricular chamber and proximal outflow tract throughout their development. The 8-kb MLC1v promoter faithfully reproduces the embryonic expression of the endogenous MLC1v mRNA. At later larval stages, weak patches of EGFP fluorescence are found on the atrial side of the atrioventricular boundary. Subsequently, an extensive lattice of MLC1v-expressing fibers extend across the mature atrial chambers of adult frog hearts and the transgene reveals the differing arrangement of muscle fibers in chamber versus outflow myocardium. The complete activity of the promoter resides within the proximal 4.5 kb of the MLC1v DNA fragment, whereas key elements regulating chamber-specific expression are present in the proximal-most 1.5 kb. Finally, we demonstrate how cardiac and craniofacial muscle expression of the MLC1v promoter can be used to diagnose mutant phenotypes in living embryos, using the injection of RNA encoding a Tbx1-engrailed repressor-fusion protein as an example.
Collapse
Affiliation(s)
- Stuart J Smith
- Division of Developmental Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
| | | | | | | | | | | |
Collapse
|
35
|
Wang TT, Tavera-Mendoza LE, Laperriere D, Libby E, MacLeod NB, Nagai Y, Bourdeau V, Konstorum A, Lallemant B, Zhang R, Mader S, White JH. Large-scale in silico and microarray-based identification of direct 1,25-dihydroxyvitamin D3 target genes. Mol Endocrinol 2005; 19:2685-95. [PMID: 16002434 DOI: 10.1210/me.2005-0106] [Citation(s) in RCA: 409] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
1alpha,25-Dihydroxyvitamin D3 [1,25(OH)2D3] regulates calcium homeostasis and controls cellular differentiation and proliferation. The vitamin D receptor (VDR) is a ligand-regulated transcription factor that recognizes cognate vitamin D response elements (VDREs) formed by direct or everted repeats of PuG(G/T)TCA motifs separated by 3 or 6 bp (DR3 or ER6). Here, we have identified direct 1,25(OH)2D3 target genes by combining 35,000+ gene microarrays and genome-wide screens for consensus DR3 and ER6 elements, and DR3 elements containing single nucleotide substitutions. We find that the effect of a nucleotide substitution on VDR binding in vitro does not predict VDRE function in vivo, because substitutions that disrupted binding in vitro were found in several functional elements. Hu133A microarray analyses, performed with RNA from human SCC25 cells treated with 1,25(OH)2D3 and protein synthesis inhibitor cycloheximide, identified more than 900 regulated genes. VDREs lying within -10 to +5 kb of 5'-ends were assigned to 65% of these genes, and VDR binding was confirmed to several elements in vivo. A screen of the mouse genome identified more than 3000 conserved VDREs, and 158 human genes containing conserved elements were 1,25(OH2)D3-regulated on Hu133A microarrays. These experiments also revealed 16 VDREs in 11 of 12 genes induced more than 10-fold in our previous microarray study, five elements in the human gene encoding the epithelial calcium channel TRPV6, as well as novel 1,25(OH2)D3 target genes implicated in regulation of cell cycle progression. The combined approaches used here thus provide numerous insights into the direct target genes underlying the broad physiological actions of 1,25(OH)2D3.
Collapse
Affiliation(s)
- Tian-Tian Wang
- Department of Physiology, McIntyre Building, Room 1128, McGill University, 3655 Drummond Street, Montreal, Quebec H3G 1Y6, Canada
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Chen S, Nakamura K, Gardner DG. 1,25-dihydroxyvitamin D inhibits human ANP gene promoter activity. ACTA ACUST UNITED AC 2005; 128:197-202. [PMID: 15837528 DOI: 10.1016/j.regpep.2004.12.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
1,25-dihydroxyvitamin D, through association with its cognate nuclear receptor, has been shown to have important effects in the cardiovascular and renal systems. We have shown previously that the liganded vitamin D receptor (VDR) inhibits hypertrophy and expression of hypertrophy-sensitive genes (i.e. those encoding atrial natriuretic peptide [ANP], brain natriuretic peptide and alpha skeletal actin) in neonatal cardiac myocytes. In the present study we confirm a time-, ligand- and retinoid X receptor-dependent, VDR-mediated suppression of human ANP gene promoter activity. Conventional deletion analysis demonstrated that the promoter region positioned between -217 and -104 is required for the VDR-dependent suppression of the hANP promoter. Mutation of two functional CArG elements, including one located within this critical region, failed to reverse the suppression. We found no evidence that the liganded VDR is capable of associating directly with regulatory elements positioned between -217 and -104. We conclude that the inhibition may arise from protein-protein interactions between the liganded VDR and stimulatory transcription factors that bind in this region.
Collapse
Affiliation(s)
- Songcang Chen
- Diabetes Center and Department of Medicine, University of California at San Francisco, 94143-0540, USA
| | | | | |
Collapse
|
37
|
Lecaudey V, Anselme I, Dildrop R, Rüther U, Schneider-Maunoury S. Expression of the zebrafish Iroquois genes during early nervous system formation and patterning. J Comp Neurol 2005; 492:289-302. [PMID: 16217788 DOI: 10.1002/cne.20765] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Iroquois genes are involved in many patterning processes during development. In particular, they act as prepattern genes to control proneural gene expression both in Drosophila and in vertebrates. In this paper, we have analyzed the expression during embryogenesis of the 11 zebrafish Iroquois genes, with special interest for nervous system formation and patterning. During the first 2 days of development, Iroquois genes are expressed in distinct domains in the neuroepithelium, as well as in groups of neuronal progenitors and neurons. They are also expressed at different stages of placodal development. These expression patterns are similar to the patterns of the murine irx genes and also show features specific to teleosts. For the zebrafish Iroquois gene family, we find both specific patterns and patterns conserved within a cluster, between paralogues, or in most genes of the family. Overall, these expression data suggest functions for the Iroquois family of transcription factors in neural and placodal patterning, neurogenesis, and neuronal specification.
Collapse
Affiliation(s)
- Virginie Lecaudey
- Biologie du Développement, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7622, Université Pierre et Marie Curie, 75252 Paris, France
| | | | | | | | | |
Collapse
|
38
|
Kelly RG, Lemonnier M, Zaffran S, Munk A, Buckingham ME. Cell history determines the maintenance of transcriptional differences between left and right ventricular cardiomyocytes in the developing mouse heart. J Cell Sci 2004; 116:5005-13. [PMID: 14625394 DOI: 10.1242/jcs.00824] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The molecular mechanisms that establish and maintain transcriptional differences between cardiomyocytes in the left and right ventricular chambers are unkown. We have previously analysed a myosin light chain 3f transgene containing an nlacZ reporter gene, which is transcribed in left but not right ventricular cardiomyocytes. In this report we examine the mechanisms involved in maintaining regionalised transgene expression. Primary cardiomyocytes prepared from left and right ventricular walls of transgenic mice were found to maintain transgene expression status in culture. However, similar cultures prepared from nontransgenic mice or rats show uniform expression after transient transfection of Mlc3f constructs, suggesting that the mechanism responsible for differential expression of the transgene between left and right ventricular cells does not operate on transiently introduced molecules. These data suggest that developmental cell history determines transgene expression status. Maintenance of transgene expression status is regulated by a cell-autonomous mechanism that is independent of DNA methylation, trichostatin A-sensitive histone deacetylation and miss-expression of transcription factors that are expressed in the left or right ventricles of the embryonic heart. Parallels between Mlc3f transgene repression in right ventricular cardiomyocytes and polycomb-mediated silencing in Drosophila suggest that Mlc3f regulatory sequences included on the transgene may contain a cellular memory module that is switched into an on or off state during early cardiogenesis. Epigenetic mechanisms may therefore be involved in maintaining patterning of the mammalian myocardium.
Collapse
Affiliation(s)
- Robert G Kelly
- CNRS URA 2578, Department of Developmental Biology, Pasteur Institute, 25 Rue du Dr Roux, Paris 75015, France.
| | | | | | | | | |
Collapse
|
39
|
Abstract
This review focuses on recent studies investigating the genetic regulatory mechanisms leading to formation of morphologically, functionally, and molecularly distinct cardiac chambers. The regulation of four representative chamber-specific genes that have been studied in detail is reviewed. These genes include the atrial-specific genes, myosin light chain-2a (MLC2a), slow myosin heavy chain-3 (slow MyHC3), and atrial natriuretic factor (ANF) and the ventricular specific gene, myosin light chain-2v (MLC2v). Comparison of these promoters reveals some generalizations about the regulatory mechanisms involved in chamber-specific gene expression but, equally, indicates the large gaps in the knowledge concerning this intriguing genetic program.
Collapse
Affiliation(s)
- Eric M Small
- Department of Cell Biology and Anatomy, University of Arizona Health Sciences Center, 1501 N. Campbell Avenue, Tucson, AZ 85724-5044, USA
| | | |
Collapse
|
40
|
Koszewski NJ, Henry KW, Lubert EJ, Gravatte H, Noonan DJ. Use of a modified yeast one-hybrid screen to identify BAF60a interactions with the Vitamin D receptor heterodimer. J Steroid Biochem Mol Biol 2003; 87:223-31. [PMID: 14698202 DOI: 10.1016/j.jsbmb.2003.09.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A modified yeast one-hybrid screen was used to isolate proteins capable of interacting with the Vitamin D receptor (VDR) heterodimer complex while driving expression from a repressor Vitamin D response element (VDRE). Four of nine independent colonies recovered in the screen coded for full-length BAF60a, a component of the mammalian SWI/SNF complex. Deletion studies in yeast were unable to localize a unique region of BAF60a responsible for interaction with the heterodimer complex, as only the full-length protein would support reporter gene expression. Pull-down analyses revealed that BAF60a displayed strong interactions with either the unliganded or liganded heterodimer complex, but neither individual receptor component alone. Transient transfection analysis in opossum kidney (OK) cells indicated that BAF60a decreased basal transcriptional activity from the negative VDRE, but had no effect on hormone-induced repression. Transcriptional activity from an enhancer VDRE also exhibited decreased basal transcriptional activity, but also augmented hormone-dependent enhancer activity, resulting in an overall increased sensitivity to hormone. In summary, BAF60a has been identified as a factor that specifically interacts with the VDR heterodimer complex using a modified yeast one-hybrid selection strategy. This suggests that BAF60a may be a link between mammalian SWI/SNF-like chromatin remodeling complexes and the VDR heterodimer.
Collapse
Affiliation(s)
- Nicholas J Koszewski
- Division of Nephrology, Bone and Mineral Metabolism, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536-0298, USA.
| | | | | | | | | |
Collapse
|
41
|
Moorman AFM, Christoffels VM. Cardiac chamber formation: development, genes, and evolution. Physiol Rev 2003; 83:1223-67. [PMID: 14506305 DOI: 10.1152/physrev.00006.2003] [Citation(s) in RCA: 461] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Concepts of cardiac development have greatly influenced the description of the formation of the four-chambered vertebrate heart. Traditionally, the embryonic tubular heart is considered to be a composite of serially arranged segments representing adult cardiac compartments. Conversion of such a serial arrangement into the parallel arrangement of the mammalian heart is difficult to understand. Logical integration of the development of the cardiac conduction system into the serial concept has remained puzzling as well. Therefore, the current description needed reconsideration, and we decided to evaluate the essentialities of cardiac design, its evolutionary and embryonic development, and the molecular pathways recruited to make the four-chambered mammalian heart. The three principal notions taken into consideration are as follows. 1) Both the ancestor chordate heart and the embryonic tubular heart of higher vertebrates consist of poorly developed and poorly coupled "pacemaker-like" cardiac muscle cells with the highest pacemaker activity at the venous pole, causing unidirectional peristaltic contraction waves. 2) From this heart tube, ventricular chambers differentiate ventrally and atrial chambers dorsally. The developing chambers display high proliferative activity and consist of structurally well-developed and well-coupled muscle cells with low pacemaker activity, which permits fast conduction of the impulse and efficacious contraction. The forming chambers remain flanked by slowly proliferating pacemaker-like myocardium that is temporally prevented from differentiating into chamber myocardium. 3) The trabecular myocardium proliferates slowly, consists of structurally poorly developed, but well-coupled, cells and contributes to the ventricular conduction system. The atrial and ventricular chambers of the formed heart are activated and interconnected by derivatives of embryonic myocardium. The topographical arrangement of the distinct cardiac muscle cells in the forming heart explains the embryonic electrocardiogram (ECG), does not require the invention of nodes, and allows a logical transition from a peristaltic tubular heart to a synchronously contracting four-chambered heart. This view on the development of cardiac design unfolds fascinating possibilities for future research.
Collapse
Affiliation(s)
- Antoon F M Moorman
- Department of Anatomy & Embryology, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
| | | |
Collapse
|
42
|
Small EM, Krieg PA. Molecular mechanisms of chamber-specific myocardial gene expression: transgenic analysis of the ANF promoter. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 67:71-9. [PMID: 12858526 DOI: 10.1101/sqb.2002.67.71] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- E M Small
- Department of Cell Biology and Anatomy, University of Arizona Health Sciences Center, Tucson, Arizona 85724, USA
| | | |
Collapse
|
43
|
Small EM, Krieg PA. Transgenic analysis of the atrialnatriuretic factor (ANF) promoter: Nkx2-5 and GATA-4 binding sites are required for atrial specific expression of ANF. Dev Biol 2003; 261:116-31. [PMID: 12941624 DOI: 10.1016/s0012-1606(03)00306-3] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The atrial natriuretic factor (ANF) gene is initially expressed throughout the myocardial layer of the heart, but during subsequent development, expression becomes limited to the atrial chambers. Mouse knockout and mammalian cell culture studies have shown that the ANF gene is regulated by combinatorial interactions between Nkx2-5, GATA-4, Tbx5, and SRF; however, the molecular mechanisms leading to chamber-specific expression are currently unknown. We have isolated the Xenopus ANF promoter in order to examine the temporal and spatial regulation of the ANF gene in vivo using transgenic embryos. The mammalian and Xenopus ANF promoters show remarkable sequence similarity, including an Nkx2-5 binding site (NKE), two GATA sites, a T-box binding site (TBE), and two SRF binding sites (SREs). Our transgenic studies show that mutation of either SRE, the TBE or the distal GATA element, strongly reduces expression from the ANF promoter. However, mutations of the NKE, the proximal GATA, or both elements together, result in relatively minor reductions in transgene expression within the myocardium. Surprisingly, mutation of these elements results in ectopic ANF promoter activity in the kidneys, facial muscles, and aortic arch artery-associated muscles, and causes persistent expression in the ventricle and outflow tract of the heart. We propose that the NKE and proximal GATA elements serve as crucial binding sites for assembly of a repressor complex that is required for atrial-specific expression of the ANF gene.
Collapse
Affiliation(s)
- Eric M Small
- Department of Cell Biology and Anatomy, University of Arizona Health Sciences Center, Tucson, AZ 85724, USA
| | | |
Collapse
|
44
|
Theokli C, Morsi El-Kadi AS, Morgan R. TALE class homeodomain gene Irx5 is an immediate downstream target for Hoxb4 transcriptional regulation. Dev Dyn 2003; 227:48-55. [PMID: 12701098 DOI: 10.1002/dvdy.10287] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The Hox genes are a family of homeodomain-containing transcription factors that determine anteroposterior identity early on in development. Although much is now known about their regulation and function, very little is known of their effector (downstream target) genes. Here, we show that the TALE class homeodomain transcription factor Irx5 is a direct, positively regulated target of Hoxb4.
Collapse
Affiliation(s)
- Christopher Theokli
- Department of Anatomy and Developmental Biology, St. George's Hospital Medical School, London, United Kingdom
| | | | | |
Collapse
|
45
|
Abstract
Myogenesis has been a system central to investigations on mechanisms of diversification within groups of differentiating cells. Diversity among cell types has been well described in striated muscle tissue at the protein and enzymatic-function levels for decades, but it is only in recent years that some understanding of the molecular mechanisms responsible for this diversity has begun to emerge. Study of the expression of the slow isoforms of the myosin heavy chain has contributed to our understanding of how cell diversity arises within skeletal and cardiac muscle. Slow MyHc isoforms are developmentally responsive to a number of cues provided by the nervous systems, the endocrine system and, later in development, to functional demands on these developing tissues. Perhaps most informative have been studies on the mechanism for regulation of slow MyHc expression in mammals and birds where studies on the calcineurin-NF-AT pathways and nuclear hormone action have been shown to control MyHC gene expression in skeletal muscle and in the developing heart. The mechanisms involved in cell diversification in myogenesis are undoubtedly more varied and complex than those currently offered to explain cell diversification, but these recent studies have broadened our understanding of the interplay between the nervous system, the endocrine system and cell lineages in controlling cell diversification. Greater focus on the first fibers and cardiomyocytes to form in the embryo are likely to bring additional insights into the mechanism crucial for establishing the patterns of diversity required for successful formation of embryonic tissues.
Collapse
Affiliation(s)
- Frank E Stockdale
- Stanford Medical Center, CCSR 1145, Stanford, California 94305-5151, USA
| | | | | |
Collapse
|
46
|
Barsony J, Prufer K. Vitamin D receptor and retinoid X receptor interactions in motion. VITAMINS AND HORMONES 2003; 65:345-76. [PMID: 12481554 DOI: 10.1016/s0083-6729(02)65071-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Vitamin D receptor (VDR) and retinoid X receptor (RXR) are members of the nuclear receptor superfamily and they bind target DNA sequences as heterodimers to regulate transcription. This article surveys the latest findings regarding the roles of dimerizing RXR in VDR function and emphasizes potential areas for future developments. We first highlight the importance of dimerization with RXR for both the ligand-independent (hair growth) and ligand-dependent functions of VDR (calcium homeostasis, bone development and mineralization, control of cell growth and differentiation). Emerging information regarding the regulatory control of dimerization based on biochemical, structural, and genetic studies is then presented. Finally, the main focus of this article is a new dynamic perspective of dimerization functions, based on recent research with fluorescent protein chimeras in living cells by microscopy. These studies revealed that both VDR and RXR constantly shuttle between the cytoplasm and the nucleus and between subnuclear compartments, and showed the transient nature of receptor--DNA and receptor--coregulator interactions. Because RXR dimerizes with most of the nuclear receptors, regulation of receptor dynamics by RXR has a broad significance.
Collapse
Affiliation(s)
- J Barsony
- Laboratory of Cell Biochemistry and Biology, National Institutes of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892, USA.
| | | |
Collapse
|
47
|
Gómez-Skarmeta JL, Modolell J. Iroquois genes: genomic organization and function in vertebrate neural development. Curr Opin Genet Dev 2002; 12:403-8. [PMID: 12100884 DOI: 10.1016/s0959-437x(02)00317-9] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We review recent work that shows that the iroquois (Iro/Irx) homeobox genes have conserved genomic organization in Drosophila and vertebrates. In addition, these genes play pivotal functions in the initial specification of the vertebrate neuroectoderm, and, in collaboration with other transcription factors, later subdivision of the anterior-posterior and dorso-ventral axis of the neuroectoderm.
Collapse
Affiliation(s)
- José Luis Gómez-Skarmeta
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
| | | |
Collapse
|
48
|
Cripps RM, Olson EN. Control of cardiac development by an evolutionarily conserved transcriptional network. Dev Biol 2002; 246:14-28. [PMID: 12027431 DOI: 10.1006/dbio.2002.0666] [Citation(s) in RCA: 232] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Formation of the heart is dependent on an intricate cascade of developmental decisions. Analysis of the molecules and mechanisms involved in the specification of cardiac cell fates, differentiation and diversification of cardiac muscle cells, and morphogenesis and patterning of different cardiac cell types has revealed an evolutionarily conserved network of signaling pathways and transcription factors that underlies these processes. The regulatory network that controls the formation of the primitive heart in fruit flies has been elaborated upon to form the complex multichambered heart of mammals. We compare and contrast the mechanisms involved in heart formation in fruit flies and mammals in the context of a network of transcriptional interactions and point to unresolved questions for the future.
Collapse
Affiliation(s)
- Richard M Cripps
- Department of Biology, University of New Mexico, Albuquerque 87131-1091, USA.
| | | |
Collapse
|
49
|
|
50
|
Abstract
Transcription factors can regulate the expression of other genes in a tissue-specific and quantitative manner and are thus major regulators of embryonic developmental processes. Several transcription factors that regulate cardiac genes specifically have been described, and the recent discovery that dominant inherited transcription factor mutations cause congenital heart defects in humans has brought direct medical relevance to the study of cardiac transcription factors in heart development. Although this field of study is extensive, several major gaps in our knowledge of the transcriptional control of heart development still exist. This review will concentrate on recent developments in the field of cardiac transcription factors and their roles in heart formation.
Collapse
Affiliation(s)
- Benoit G Bruneau
- Division of Cardiovascular Research and Programme in Developmental Biology, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.
| |
Collapse
|