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Canse C, Yildirim E, Yaba A. Overview of junctional complexes during mammalian early embryonic development. Front Endocrinol (Lausanne) 2023; 14:1150017. [PMID: 37152932 PMCID: PMC10158982 DOI: 10.3389/fendo.2023.1150017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 02/28/2023] [Indexed: 05/09/2023] Open
Abstract
Cell-cell junctions form strong intercellular connections and mediate communication between blastomeres during preimplantation embryonic development and thus are crucial for cell integrity, polarity, cell fate specification and morphogenesis. Together with cell adhesion molecules and cytoskeletal elements, intercellular junctions orchestrate mechanotransduction, morphokinetics and signaling networks during the development of early embryos. This review focuses on the structure, organization, function and expressional pattern of the cell-cell junction complexes during early embryonic development. Understanding the importance of dynamic junction formation and maturation processes will shed light on the molecular mechanism behind developmental abnormalities of early embryos during the preimplantation period.
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Affiliation(s)
- Ceren Canse
- Faculty of Medicine, Yeditepe University, Istanbul, Türkiye
| | - Ecem Yildirim
- Department of Histology and Embryology, Yeditepe University Faculty of Medicine, Istanbul, Türkiye
| | - Aylin Yaba
- Department of Histology and Embryology, Yeditepe University Faculty of Medicine, Istanbul, Türkiye
- *Correspondence: Aylin Yaba,
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2
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Jeong Y, Ock S, Yoo JG, Yu D, Choi I. The Cxadr–Adam10 complex plays pivotal roles in tight junction integrity and early trophoblast development in mice. Mol Reprod Dev 2019; 86:1628-1638. [DOI: 10.1002/mrd.23250] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 07/16/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Yelin Jeong
- Division of Animal and Dairy Sciences, College of Agriculture and Life SciencesChungnam National UniversityDaejeon Republic of Korea
- Disease Model Research Laboratory, Genome Editing Research CenterKorea Research Institute of Bioscience and Biotechnology (KRIBB)Daejeon Republic of Korea
| | - Sun‐A Ock
- National Institute of Animal ScienceRural Development AdministrationJeollabuk‐do Republic of Korea
| | - Jae Gyu Yoo
- National Institute of Animal ScienceRural Development AdministrationJeollabuk‐do Republic of Korea
| | - Dae‐Yeul Yu
- Disease Model Research Laboratory, Genome Editing Research CenterKorea Research Institute of Bioscience and Biotechnology (KRIBB)Daejeon Republic of Korea
- Department of Functional GenomicsUniversity of Science and TechnologyDaejeon Republic of Korea
| | - Inchul Choi
- Division of Animal and Dairy Sciences, College of Agriculture and Life SciencesChungnam National UniversityDaejeon Republic of Korea
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3
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Kwon J, Park S, Seong MJ, Choi I, Kim NH. Cytoplasmic polyadenylation element binding protein 2 (CPEB2) is required for tight-junction assembly for establishment of porcine trophectoderm epithelium. Reprod Fertil Dev 2019; 31:412-419. [DOI: 10.1071/rd18098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/27/2018] [Indexed: 11/23/2022] Open
Abstract
Cytoplasmic polyadenylation element binding protein (CPEB) is an RNA-binding protein that promotes elongation of poly(A) tails and regulates mRNA translation. CPEB depletion in mammary epithelium is known to disrupt tight-junction (TJ) assembly via mislocalisation of tight junction protein 1 (TJP1), but the role of CPEB in the biological functions associated with TJs has not yet been studied. The objective of this study was to investigate the roles of CPEB2 during porcine parthenote development. CPEB2 was detected in both the nuclei and apical cytoplasm at the 4- and 8-cell stages and was localised to cell–cell contact after the initiation of the morula stage. Its depletion led to retarded blastocyst formation caused by impaired TJ assembly. Moreover, transcription of TJ-associated genes, including TJP1, Coxsackie virus and adenovirus receptor (CXADR) and occludin (OCLN), was not affected, but the corresponding proteins were not properly localised at the apical cell membrane in morulae, suggesting that CPEB2 confers mRNA stability or determines subcellular localisation for translation. Remarkably reduced relative levels of TJP1 transcripts bearing the 3′-untranslated region were noted, indicating that CPEB2 mediates TJP1 mRNA stability. In conclusion, our findings demonstrate that because of its regulation of TJP1, CPEB2 is required for TJ assembly during porcine blastocyst development.
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4
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Shin MY, Lee SE, Son YJ, Park YG, Jeong SG, Kim EY, Park SP. Lysophosphatidic acid accelerates development of porcine embryos by activating formation of the blastocoel. Mol Reprod Dev 2017; 85:62-71. [PMID: 29226557 DOI: 10.1002/mrd.22938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/29/2017] [Indexed: 01/14/2023]
Abstract
Culture media modifications, including the addition of various factors, are important for the in vitro production of oocytes and embryos. In this study, we investigated the effects of lysophosphatidic acid (LPA) on porcine embryo development. Porcine parthenogenetic embryos were cultured with 0, 0.1, 1, and 10 μM LPA for 7 days, or cultured in basic medium until Day 4 and then treated with LPA from Days 4 to 7. No difference in the in vitro development of embryos cultured with LPA for 7 days was observed. Conversely, rates of blastocyst and over-expanded blastocyst formation were higher in the 0.1 and 1 µM LPA-treated versus the other groups of embryos treated from Days 4 to 7. Moreover, formation of early blastocysts occurred earlier and embryo size was larger in LPA-treated compared to control embryos. Expression of Connexin 43 and gap junction and cell adhesion-related genes (GJC1 and CDH1, respectively) was also higher in LPA-treated compared to control embryos. Despite no difference in the blastocyst total cell number between groups, the apoptotic index was lower in the LPA-treated group than in the control group; indeed, BCL2L1 (B-cell lymphoma 2-like protein 1) expression increased while BAK (Bcl-2 homologous antagonist killer) decreased in the LPA-treated group. Thus, addition of LPA to the medium from Days 4 to 7 of culture improves blastocyst formation and aids the development of preimplantation embryos.
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Affiliation(s)
- Min-Young Shin
- Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Stem Cell Research Center, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea
| | - Seung-Eun Lee
- Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Stem Cell Research Center, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea
| | - Yeo-Jin Son
- Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Stem Cell Research Center, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea
| | - Yun-Gwi Park
- Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Stem Cell Research Center, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea
| | - Sang-Gi Jeong
- Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Stem Cell Research Center, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea
| | - Eun-Young Kim
- Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Stem Cell Research Center, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Mirae Cell Bio, Gwangjin-gu, Seoul, Korea
| | - Se-Pill Park
- Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Stem Cell Research Center, Jeju National University, Jeju, Jeju Special Self-Governing Province, Korea.,Mirae Cell Bio, Gwangjin-gu, Seoul, Korea
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5
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Leung CY, Zhu M, Zernicka-Goetz M. Polarity in Cell-Fate Acquisition in the Early Mouse Embryo. Curr Top Dev Biol 2016; 120:203-34. [PMID: 27475853 DOI: 10.1016/bs.ctdb.2016.04.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Establishing polarity is a fundamental part of embryogenesis and can be traced back to the earliest developmental stages. It can be achieved in one of two ways: through the preexisting polarization of germ cells before fertilization or via symmetry breaking after fertilization. In mammals, it seems to be the latter, and we will discuss the various cytological and molecular events that lead up to this event, its mechanisms and the consequences. In mammals, the first polarization event occurs in the preimplantation period, when the embryo is but a cluster of cells, free-floating in the oviduct. This provides a unique, autonomous system to study the de novo polarization that is essential to life. In this review, we will cover modern and past studies on the polarization of the early embryo, using the mouse as a model system, as well as hypothesizing the potential implications and functions of the biological events involved.
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Affiliation(s)
- C Y Leung
- University of Cambridge, Cambridge, United Kingdom
| | - M Zhu
- University of Cambridge, Cambridge, United Kingdom
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Cheng X, Xu S, Song C, He L, Lian X, Liu Y, Wei J, Pang L, Wang S. Roles of ERα during mouse trophectoderm lineage differentiation: revealed by antagonist and agonist of ERα. Dev Growth Differ 2016; 58:327-38. [PMID: 27037955 DOI: 10.1111/dgd.12276] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 02/04/2016] [Accepted: 02/20/2016] [Indexed: 11/26/2022]
Abstract
During mouse early embryogenesis, blastomeres increase in number by the morula stage. Among them, the outer cells are polarized and differentiated into trophectoderm (TE), while the inner cells remain unpolarized and give rise to inner cell mass (ICM). TE provides an important liquid environment for ICM development. In spite of extensive research, the molecular mechanisms underlying TE formation are still obscure. In order to investigate the roles of estrogen receptor α (ERα) in this course, mouse 8-cell embryos were collected and cultured in media containing ERα specific antagonist MPP and/or agonist PPT. The results indicated that MPP treatment inhibits blastocyst formation in a dose-dependent manner, while PPT, at proper concentration, promotes the cavitation ratio of mouse embryos. Immunofluorescence staining results showed that MPP significantly decreased the nuclear expression of CDX2 in morula, but no significant changes of OCT4 were observed. Moreover, after MPP treatment, the expression levels of the genes related to TE specification, Tead4, Gata3 and Cdx2, were significantly reduced. Overall, these results indicated that ERα might affect mouse embryo cavitation by regulating TE lineage differentiation.
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Affiliation(s)
- Xiaoxiang Cheng
- Cellular and Developmental Engineering Center, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Songhua Xu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Chanchan Song
- Cellular and Developmental Engineering Center, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Lin He
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Xiuli Lian
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Yue Liu
- Cellular and Developmental Engineering Center, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Jianen Wei
- Cellular and Developmental Engineering Center, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China.,Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Lili Pang
- Cellular and Developmental Engineering Center, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Shie Wang
- Cellular and Developmental Engineering Center, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China.,Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
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7
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Lee SH, Kwon JW, Choi I, Kim NH. Expression and function of transcription factor AP-2? in early embryonic development of porcine parthenotes. Reprod Fertil Dev 2015; 28:RD14198. [PMID: 25562461 DOI: 10.1071/rd14198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 12/03/2014] [Indexed: 01/05/2023] Open
Abstract
Transcription factor AP-2? (TFAP2C) is a member of the transcription factor activating enhancer binding protein (AP) family. In the present study we determined the temporal and spatial expression patterns of TFAP2C in porcine parthenotes during preimplantation development. Porcine TFAP2C transcripts were expressed at all stages of preimplantation development, with highest expression at the 8-cell stage. In contrast with the mouse, TFAP2C protein was not restricted to the trophectoderm and was also detected in the ICM in blastocyst stage porcine parthenotes. In knockdown (KD) experiments, most TFAP2C-depleted embryos were arrested before the compacted 8-cell stage. This developmental failure is attributed to abnormal expression of genes involved in cell adhesion, tight junction biogenesis and cell proliferation. Interestingly, although the conserved region 4 (CR4) of the porcine OCT4 5? upstream regionlacked the AP2C-binding motif, OCT4 transcript levels were elevated in porcine TFAP2C-KD 8-cell embryos, suggesting TFAP2C may be involved in the regulation of OCT4 in porcine embryos through other mechanisms. In summary, the results suggest that TFAP2C is necessary for the transition from de novo transcript synthesis by activation to compaction and further development, and the different expression patterns of TFAP2C in porcine embryos may reflect species-specific functions during preimplantation embryo development.
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8
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Kojima Y, Tam OH, Tam PPL. Timing of developmental events in the early mouse embryo. Semin Cell Dev Biol 2014; 34:65-75. [PMID: 24954643 DOI: 10.1016/j.semcdb.2014.06.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 06/04/2014] [Accepted: 06/11/2014] [Indexed: 01/29/2023]
Abstract
The timing of developmental events during early mouse development has been investigated in embryos that have been subject to experimental manipulation of cell number and tissue mass. These phenomenological studies revealed that the timing of preimplantation events, such as compaction, formation of blastocyst cavity and lineage allocation is correlated with the rounds of cleavage division or DNA replication of the blastomeres. Timing of postimplantation processes, such as formation of proamniotic cavity and onset of gastrulation is sensitive to cell number and probably the tissue mass, which may be measured by a mechanosensory signaling mechanism. Developmental changes in these two physical attributes are correlated with the cell proliferative activity and the growth trajectory of the whole embryo prior to the transit to organogenesis. During organogenesis, timing of morphogenesis appears to be regulated by individual devices that could be uncoupled during compensatory growth. Insights of the timing mechanism may be gleaned from the analysis of genomic activity associated with the transition through developmental milestones.
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Affiliation(s)
- Yoji Kojima
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501, Japan.
| | - Oliver H Tam
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
| | - Patrick P L Tam
- Embryology Unit, Children's Medical Research Institute and Sydney Medical School, University of Sydney, Westmead, NSW 2145, Australia.
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Dörfel MJ, Westphal JK, Bellmann C, Krug SM, Cording J, Mittag S, Tauber R, Fromm M, Blasig IE, Huber O. CK2-dependent phosphorylation of occludin regulates the interaction with ZO-proteins and tight junction integrity. Cell Commun Signal 2013; 11:40. [PMID: 23758859 PMCID: PMC3695765 DOI: 10.1186/1478-811x-11-40] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 06/04/2013] [Indexed: 01/28/2023] Open
Abstract
Background Casein kinase 2 (CK2) is a ubiquitously expressed Ser/Thr kinase with multiple functions in the regulation of cell proliferation and transformation. In targeting adherens and tight junctions (TJs), CK2 modulates the strength and dynamics of epithelial cell-cell contacts. Occludin previously was identified as a substrate of CK2, however the functional consequences of CK2-dependent occludin phosphorylation on TJ function were unknown. Results Here, we present evidence that phosphorylation of a Thr400-XXX-Thr404-XXX-Ser408 motif in the C-terminal cytoplasmic tail of human occludin regulates assembly/disassembly and barrier properties of TJs. In contrast to wildtype and T400A/T404A/S408A-mutated occludin, a phospho-mimetic Occ-T400E/T404E/S408E construct was impaired in binding to ZO-2. Interestingly, pre-phosphorylation of a GST-Occ C-terminal domain fusion protein attenuated binding to ZO-2, whereas, binding to ZO-1 was not affected. Moreover, Occ-T400E/T404E/S408E showed delayed reassembly into TJs in Ca2+-switch experiments. Stable expression of Occ-T400E/T404E/S408E in MDCK C11 cells augments barrier properties in enhancing paracellular resistance in two-path impedance spectroscopy, whereas expression of wildtype and Occ-T400A/T404A/S408A did not affect transepithelial resistance. Conclusions These results suggest an important role of CK2 in epithelial tight junction regulation. The occludin sequence motif at amino acids 400–408 apparently represents a hotspot for Ser/Thr-kinase phosphorylation and depending on the residue(s) which are phosphorylated it differentially modulates the functional properties of the TJ.
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Affiliation(s)
- Max J Dörfel
- Institute of Biochemistry II, Jena University Hospital, Friedrich-Schiller-University Jena, Nonnenplan 2, 07743 Jena, Germany.
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10
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Insights into the role of cell-cell junctions in physiology and disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 306:187-221. [PMID: 24016526 DOI: 10.1016/b978-0-12-407694-5.00005-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Contacting cells establish different classes of intricate structures at the cell-cell junctions. These structures are of increasing research interest as they regulate a broad variety of processes in development and disease. Further, in vitro studies are revealing that various cell-cell interaction proteins are involved not only in cell-cell processes but also in many additional aspects of physiology, such as migration and apoptosis. This chapter reviews the basic classification of cell-cell junctional structures and some of their representative proteins. Their roles in development and disease are briefly outlined, followed by a section on contemporary methods for probing cell-cell interactions and some recent developments. This chapter concludes with a few suggestions for potential research directions to further develop this promising area of study.
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Expression of ZO-1 and occludin at mRNA and protein level during preimplantation development of the pig parthenogenetic diploids. ZYGOTE 2011; 20:147-58. [DOI: 10.1017/s0967199410000705] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SummaryExpression of mRNAs and proteins of ZO-1 and occludin was analyzed in pig oocytes and parthenogenetic diploid embryos during preimplantation development using real-time RT-PCR, western blotting and immunocytochemistry. All germinal vesicle (GV) and metaphase (M)II oocytes and preimplantation embryos expressed mRNAs and proteins of ZO-1 and occludin. mRNA levels of both ZO-1 and occludin decreased significantly from GV to MII, but increased at the 2-cell stage followed by temporal decrease during the early and late 4-cell stages. Then, both mRNAs increased after compaction. Relative concentration of zo1α− was highest in 2-cell embryos, while zo1α+ was expressed from the morula stage. Occludin expression greatly increased after the morula stage and was highest in expanded blastocysts. Western blotting analysis showed constant expression of ZO-1α− throughout preimplantation development and limited translation of ZO-1α+ from the blastocysts, and species-specific expression pattern of occludin. Immunocytochemistry analysis revealed homogeneous distribution of ZO-1 and occludin in the cytoplasm with moderately strong fluorescence in the vicinity of the contact region between blastomeres, around the nuclei in the 2-cell to late 4-cell embryos, and clear network localization along the cell-boundary region in embryos after the morula stage. Present results show that major TJ proteins, ZO-1 and occludin are expressed in oocytes and preimplantation embryos, and that ZO-1α+ is transcribed by zygotic gene activation and translated from early blastocysts with prominent increase of occludin at the blastocyst stage.
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Khailova L, Dvorak K, Arganbright KM, Williams CS, Halpern MD, Dvorak B. Changes in hepatic cell junctions structure during experimental necrotizing enterocolitis: effect of EGF treatment. Pediatr Res 2009; 66:140-4. [PMID: 19390485 PMCID: PMC2818015 DOI: 10.1203/pdr.0b013e3181aa3198] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Necrotizing enterocolitis (NEC) is a devastating disease of premature babies. Previously, we have shown that EGF reduces NEC and that overproduction of hepatic TNF-alpha is associated with intestinal damage. Leakage of TNF-alpha may be a consequence of epithelial hepatic cellular junction dysfunction. The aim of this study was to investigate changes in the composition of hepatic tight junctions (TJs) and adherens junctions (AJs). Using an established rat model of NEC, animals were divided into the following groups: dam fed (DF), formula fed (NEC), or fed with formula supplemented with EGF (EGF). Serum EGF and histologic localization of major TJ and AJ proteins were evaluated. Distribution patterns of hepatic TJ and AJ proteins were significantly altered in the NEC group compared with those in DF or EGF groups. Cytoplasmic accumulation of occludin, claudin-2, and ZO-1 with reduction of claudin-3 signal was detected in the liver of NEC rats. Localization of beta-catenin was associated with the hepatocyte membrane in EGF and DF groups, but diffused in the NEC group. These data show that hepatic cellular junctions are significantly altered during NEC pathogenesis. EGF-mediated reduction of experimental NEC is associated with protection of hepatic integrity and structure.
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Affiliation(s)
- Ludmila Khailova
- Department of Pediatrics, University of Arizona, Tucson, Arizona 85724, USA
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13
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Tight junction protein ZO-2 expression and relative function of ZO-1 and ZO-2 during mouse blastocyst formation. Exp Cell Res 2008; 314:3356-68. [PMID: 18817772 DOI: 10.1016/j.yexcr.2008.08.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 08/01/2008] [Accepted: 08/25/2008] [Indexed: 01/02/2023]
Abstract
Apicolateral tight junctions (TJs) between epithelial cells are multiprotein complexes regulating membrane polarity and paracellular transport and also contribute to signalling pathways affecting cell proliferation and gene expression. ZO-2 and other ZO family members form a sub-membranous scaffold for binding TJ constituents. We investigated ZO-2 contribution to TJ biogenesis and function during trophectoderm epithelium differentiation in mouse preimplantation embryos. Our data indicate that ZO-2 is expressed from maternal and embryonic genomes with maternal ZO-2 protein associated with nuclei in zygotes and particularly early cleavage stages. Embryonic ZO-2 assembled at outer blastomere apicolateral junctional sites from the late 16-cell stage. Junctional ZO-2 first co-localised with E-cadherin in a transient complex comprising adherens junction and TJ constituents before segregating to TJs after their separation from the blastocyst stage (32-cell onwards). ZO-2 siRNA microinjection into zygotes or 2-cell embryos resulted in specific knockdown of ZO-2 mRNA and protein within blastocysts. Embryos lacking ZO-2 protein at trophectoderm TJs exhibited delayed blastocoel cavity formation but underwent normal cell proliferation and outgrowth morphogenesis. Quantitative analysis of trophectoderm TJs in ZO-2-deficient embryos revealed increased assembly of ZO-1 but not occludin, indicating ZO protein redundancy as a compensatory mechanism contributing to the mild phenotype observed. In contrast, ZO-1 knockdown, or combined ZO-1 and ZO-2 knockdown, generated a more severe inhibition of blastocoel formation indicating distinct roles for ZO proteins in blastocyst morphogenesis.
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14
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Wang H, Ding T, Brown N, Yamamoto Y, Prince LS, Reese J, Paria BC. Zonula occludens-1 (ZO-1) is involved in morula to blastocyst transformation in the mouse. Dev Biol 2008; 318:112-25. [PMID: 18423437 PMCID: PMC2442465 DOI: 10.1016/j.ydbio.2008.03.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2007] [Revised: 02/13/2008] [Accepted: 03/06/2008] [Indexed: 12/15/2022]
Abstract
It is unknown whether or not tight junction formation plays any role in morula to blastocyst transformation that is associated with development of polarized trophoblast cells and fluid accumulation. Tight junctions are a hallmark of polarized epithelial cells and zonula occludens-1 (ZO-1) is a known key regulator of tight junction formation. Here we show that ZO-1 protein is first expressed during compaction of 8-cell embryos. This stage-specific appearance of ZO-1 suggests its participation in morula to blastocyst transition. Consistent with this idea, we demonstrate that ZO-1 siRNA delivery inside the blastomeres of zona-weakened embryos using electroporation not only knocks down ZO-1 gene and protein expressions, but also inhibits morula to blastocyst transformation in a concentration-dependent manner. In addition, ZO-1 inactivation reduced the expression of Cdx2 and Oct-4, but not ZO-2 and F-actin. These results provide the first evidence that ZO-1 is involved in blastocyst formation from the morula by regulating accumulation of fluid and differentiation of nonpolar blastomeres to polar trophoblast cells.
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Affiliation(s)
- Hehai Wang
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Tianbing Ding
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Naoko Brown
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Yasutoshi Yamamoto
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Lawrence S. Prince
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Jeff Reese
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - B. C. Paria
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
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15
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Eckert JJ, Fleming TP. Tight junction biogenesis during early development. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:717-28. [DOI: 10.1016/j.bbamem.2007.09.031] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 09/13/2007] [Accepted: 09/17/2007] [Indexed: 01/12/2023]
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16
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Cereijido M, Contreras RG, Shoshani L, Flores-Benitez D, Larre I. Tight junction and polarity interaction in the transporting epithelial phenotype. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1778:770-93. [PMID: 18028872 DOI: 10.1016/j.bbamem.2007.09.001] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Revised: 08/28/2007] [Accepted: 09/03/2007] [Indexed: 12/21/2022]
Abstract
Development of tight junctions and cell polarity in epithelial cells requires a complex cellular machinery to execute an internal program in response to ambient cues. Tight junctions, a product of this machinery, can act as gates of the paracellular pathway, fences that keep the identity of plasma membrane domains, bridges that communicate neighboring cells. The polarization internal program and machinery are conserved in yeast, worms, flies and mammals, and in cell types as different as epithelia, neurons and lymphocytes. Polarization and tight junctions are dynamic features that change during development, in response to physiological and pharmacological challenges and in pathological situations like infection.
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Affiliation(s)
- Marcelino Cereijido
- Department of Physiology, Biophysics and Neurosciences, CINVESTAV, AP 14-740, México D.F. 07000, México.
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17
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Crosstalk of tight junction components with signaling pathways. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1778:729-56. [PMID: 17950242 DOI: 10.1016/j.bbamem.2007.08.018] [Citation(s) in RCA: 565] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 08/03/2007] [Accepted: 08/16/2007] [Indexed: 12/28/2022]
Abstract
Tight junctions (TJs) regulate the passage of ions and molecules through the paracellular pathway in epithelial and endothelial cells. TJs are highly dynamic structures whose degree of sealing varies according to external stimuli, physiological and pathological conditions. In this review we analyze how the crosstalk of protein kinase C, protein kinase A, myosin light chain kinase, mitogen-activated protein kinases, phosphoinositide 3-kinase and Rho signaling pathways is involved in TJ regulation triggered by diverse stimuli. We also report how the phosphorylation of the main TJ components, claudins, occludin and ZO proteins, impacts epithelial and endothelial cell function.
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Eckert JJ, Houghton FD, Hawkhead JA, Balen AH, Leese HJ, Picton HM, Cameron IT, Fleming TP. Human embryos developing in vitro are susceptible to impaired epithelial junction biogenesis correlating with abnormal metabolic activity. Hum Reprod 2007; 22:2214-24. [PMID: 17623723 DOI: 10.1093/humrep/dem147] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Blastocyst biogenesis occurs over several cell cycles during the preimplantation period comprising the gradual expression and membrane assembly of junctional protein complexes which distinguish the outer epithelial trophectoderm (TE) cells from the inner cell mass (ICM). In the human, TE integrity and the formation of a junctional seal can often be impaired. Embryos likely to result in a successful pregnancy after transfer are mostly selected according to morphological criteria. Recent data suggest that non-invasive measurement of amino acid turnover may be useful to complement such morphological scores. Whether morphological and metabolic criteria can be linked to poor TE differentiation thereby underpinning developmental predictions mechanistically remains unknown. METHODS We examined TE intercellular junction formation in human embryos by immunofluorescence and confocal microscopy and correlated this process with morphological criteria and amino acid turnover during late cleavage. RESULTS Our results show that TE differentiation may be compromised by failure of membrane assembly of specific junction constituents. This abnormality relates more closely to metabolic profiles than morphological criteria. CONCLUSION Our data identify that amino acid turnover can predict TE differentiation. These findings are the first to link two mechanisms, metabolism and junction membrane assembly, which contribute to early embryo development.
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Affiliation(s)
- Judith J Eckert
- School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton, UK.
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19
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Hamatani T, Ko MS, Yamada M, Kuji N, Mizusawa Y, Shoji M, Hada T, Asada H, Maruyama T, Yoshimura Y. Global gene expression profiling of preimplantation embryos. Hum Cell 2007; 19:98-117. [PMID: 17204093 DOI: 10.1111/j.1749-0774.2006.00018.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Preimplantation development is marked by four major events: the transition of maternal transcripts to zygotic transcripts, compaction, the first lineage differentiation into inner cell mass and trophectoderm, and implantation. The scarcity of the materials of preimplantation embryos, both in size (diameter < 100 microm) and in quantity (only a few to tens of oocytes from each ovulation), has hampered molecular analysis of preimplantation embryos. Recent progress in RNA amplification methods and microarray platforms, including genes unique to preimplantation embryos, allow us to apply global gene expression profiling to the study of preimplantation embryos. Our gene expression profiling during preimplantation development revealed the distinctive patterns of maternal RNA degradation and embryonic gene activation, including two major transient waves of de novo transcription. The first wave corresponds to zygotic genome activation (ZGA). The second wave, mid-preimplantation gene activation (MGA), contributes dramatic morphological changes during late preimplantation development. Further expression profiling of embryos treated with inhibitors of transcription or translation revealed that the translation of maternal RNA is required for the initiation of ZGA, suggesting a cascade of gene activation from maternal RNA/protein sets to ZGA gene sets and thence to MGA gene sets. To date, several reports of microarray experiments using mouse and human preimplantation embryos have been published. The identification of a large number of genes and multiple signaling pathways involved at each developmental stage by such global gene expression profiling accelerates understanding of molecular mechanisms underlining totipotency/pluripotency and programs of early mammalian development.
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Affiliation(s)
- Toshio Hamatani
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan.
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20
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González-Mariscal L, Lechuga S, Garay E. Role of tight junctions in cell proliferation and cancer. ACTA ACUST UNITED AC 2007; 42:1-57. [PMID: 17502225 DOI: 10.1016/j.proghi.2007.01.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The acquisition of a cancerous phenotype by epithelial cells involves the disruption of intercellular adhesions. The reorganization of the E-cadherin/beta-catenin complex in adherens junctions during cell transformation is widely recognized. Instead the implication of tight junctions (TJs) in this process is starting to be unraveled. The aim of this article is to review the role of TJ proteins in cell proliferation and cancer.
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Affiliation(s)
- Lorenza González-Mariscal
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Ave. Instituto Politécnico Nacional 2508, México, DF 07360, México.
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21
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Madan P, Rose K, Watson AJ. Na/K-ATPase beta1 subunit expression is required for blastocyst formation and normal assembly of trophectoderm tight junction-associated proteins. J Biol Chem 2007; 282:12127-34. [PMID: 17317668 DOI: 10.1074/jbc.m700696200] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Na/K-ATPase plays an important role in mediating blastocyst formation. Despite the expression of multiple Na/K-ATPase alpha and beta isoforms during mouse preimplantation development, only the alpha1 and beta1 isoforms have been localized to the basolateral membrane regions of the trophectoderm. The aim of the present study was to selectively down-regulate the Na/K-ATPase beta1 subunit employing microinjection of mouse 1 cell zygotes with small interfering RNA (siRNA) oligos. Experiments comprised of non-injected controls and two groups microinjected with either Stealthtrade mark Na/K-ATPase beta1 subunit oligos or nonspecific Stealthtrade mark siRNA as control. Development to the 2-, 4-, 8-, and 16-cell and morula stages did not vary between the three groups. However, only 2.3% of the embryos microinjected with Na/K-ATPase beta1 subunit siRNA oligos developed to the blastocyst stage as compared with 73% for control-injected and 91% for non-injected controls. Na/K-ATPase beta1 subunit down-regulation was validated by employing reverse transcription-PCR and whole-mount immunofluorescence methods to demonstrate that Na/K-ATPase beta1 subunit mRNAs and protein were not detectable in beta1 subunit siRNA-microinjected embryos. Aggregation chimera experiments between beta1 subunit siRNA-microinjected embryos and controls demonstrated that blockade of blastocyst formation was reversible. The distribution of Na/K-ATPase alpha1 and tight junction-associated proteins occludin and ZO-1 were compared among the three treatment groups. No differences in protein distribution were observed between control groups; however, all three polypeptides displayed an aberrant distribution in Na/K-ATPase beta1 subunit siRNA-microinjected embryos. Our results demonstrate that the beta1 subunit of the Na/K-ATPase is required for blastocyst formation and that this subunit is also required to maintain a normal Na/K-ATPase distribution and localization of tight junction-associated polypeptides during preimplantation development.
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Affiliation(s)
- Pavneesh Madan
- Department of Obstetrics and Gynaecology, University of Western Ontario, Children's Health Research Institute-Victoria Research Laboratories, London, Ontario N6A 4G5, Canada
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22
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Violette MI, Madan P, Watson AJ. Na+/K+-ATPase regulates tight junction formation and function during mouse preimplantation development. Dev Biol 2006; 289:406-19. [PMID: 16356488 DOI: 10.1016/j.ydbio.2005.11.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Revised: 10/31/2005] [Accepted: 11/04/2005] [Indexed: 01/08/2023]
Abstract
Research applied to the early embryo is required to effectively treat human infertility and to understand the primary mechanisms controlling development to the blastocyst stage. The present study investigated whether the Na(+)/K(+)-ATPase regulates tight junction formation and function during blastocyst formation. To investigate this hypothesis, three experimental series were conducted. The first experiments defined the optimal dose and treatment time intervals for ouabain (a potent and specific inhibitor of the Na(+)/K(+)-ATPase) treatment. The results demonstrated that mouse embryos maintained a normal development to the blastocyst stage following a 6-h ouabain treatment. The second experiments investigated the effects of ouabain treatment on the distribution of ZO-1 and occludin (tight junction associated proteins). Ouabain treatment (up to 6 h) or culture in K(+)-free medium (up to 6 h) resulted in the appearance of a discontinuous ZO-1 protein distribution and a loss of occludin immunofluorescence. The third set of experiments examined the influence of ouabain treatment on tight junction function. Ouabain treatment or culture in K(+)-free medium affected tight junction permeability as indicated by an increase in the proportion of treated embryos accumulating both 4 kDa and 40 kDa fluorescein isothiocyanate (FITC)-dextran into their blastocyst cavities. The results indicate that the Na(+)/K(+)-ATPase is a potent regulator of tight junction formation and function during mouse preimplantation development.
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Affiliation(s)
- Michelle I Violette
- Department of Physiology and Pharmacology, The University of Western Ontario, The Children's Health Research Institute-Victoria Research Laboratories, 800 Commissioners Road, London, Ontario, Canada N6A 4G5
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23
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Eckert JJ, McCallum A, Mears A, Rumsby MG, Cameron IT, Fleming TP. Relative contribution of cell contact pattern, specific PKC isoforms and gap junctional communication in tight junction assembly in the mouse early embryo. Dev Biol 2005; 288:234-47. [PMID: 16271712 DOI: 10.1016/j.ydbio.2005.09.037] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 09/01/2005] [Accepted: 09/22/2005] [Indexed: 01/12/2023]
Abstract
In mouse early development, cell contact patterns regulate the spatial organization and segregation of inner cell mass (ICM) and trophectoderm epithelium (TE) during blastocyst morphogenesis. Progressive membrane assembly of tight junctional (TJ) proteins in the differentiating TE during cleavage is upregulated by cell contact asymmetry (outside position) and suppressed within the ICM by cell contact symmetry (inside position). This is reversible, and immunosurgical isolation of the ICM induces upregulation of TJ assembly in a sequence that broadly mimics that occurring during blastocyst formation. The mechanism relating cell contact pattern and TJ assembly was investigated in the ICM model with respect to PKC-mediated signaling and gap junctional communication. Our results indicate that complete cell contact asymmetry is required for TJ biogenesis and acts upstream of PKC-mediated signaling. Specific inhibition of two PKC isoforms, PKCdelta and zeta, revealed that both PKC activities are required for membrane assembly of ZO-2 TJ protein, while only PKCzeta activity is involved in regulating ZO-1alpha+ membrane assembly, suggesting different mechanisms for individual TJ proteins. Gap junctional communication had no apparent influence on either TJ formation or PKC signaling but was itself affected by changes of cell contact patterns. Our data suggest that the dynamics of cell contact patterns coordinate the spatial organization of TJ formation via specific PKC signaling pathways during blastocyst biogenesis.
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Affiliation(s)
- Judith J Eckert
- University of Southampton, School of Biological Sciences, Bassett Crescent East, Southampton, SO16 7PX, UK.
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24
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Fink MP, Delude RL. Epithelial Barrier Dysfunction: A Unifying Theme to Explain the Pathogenesis of Multiple Organ Dysfunction at the Cellular Level. Crit Care Clin 2005; 21:177-96. [PMID: 15781156 DOI: 10.1016/j.ccc.2005.01.005] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The multiple organ dysfunction syndrome (MODS) is the most common cause of death among patients requiring care in an ICU. There is widespread agreement that MODS is the clinical manifestation of a dysregulated inflammatory response. This article, however, summarizes some tantalizing data to support the view that derangements in the formation or function of specialized structures in epithelial cells, tight junctions, may be a key factor leading to lung, liver, gut, and perhaps kidney dysfunction associated with such conditions as sepsis and acute lung injury syndrome that are caused by dysregulated inflammatory processes.
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Affiliation(s)
- Mitchell P Fink
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, 616 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261, USA.
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25
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Assémat E, Vinot S, Gofflot F, Linsel-Nitschke P, Illien F, Châtelet F, Verroust P, Louvet-Vallée S, Rinninger F, Kozyraki R. Expression and role of cubilin in the internalization of nutrients during the peri-implantation development of the rodent embryo. Biol Reprod 2004; 72:1079-86. [PMID: 15616221 DOI: 10.1095/biolreprod.104.036913] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Histiotrophic nutrition is essential during the peri-implantation development in rodents, but little is known about receptors involved in protein and lipid endocytosis derived from the endometrium and the uterine glands. Previous studies suggested that cubilin, a multiligand receptor for vitamin, iron, and protein uptake in the adult, might be important in this process, but the onset of its expression and function is not known. In this study, we analyzed the expression of cubilin in the pre- and early post-implantation rodent embryo and tested its potential function in protein and cholesterol uptake. Using morphological and Western blot analysis, we showed that cubilin first appeared at the eight-cell stage. It was expressed by the maternal-fetal interfaces, trophectoderm and visceral endoderm, but also by the future neuroepithelial cells and the developing neural tube. At all these sites, cubilin was localized at the apical pole of the cells exposed to the maternal environment or to the amniotic and neural tube cavities, and had a very similar distribution to megalin, a member of the LDLR gene family and a coreceptor for cubilin in adult tissues. To analyze cubilin function, we followed endocytosis of apolipoprotein A-I and HDL cholesterol, nutrients normally present in the uterine glands and essential for embryonic growth. We showed that internalization of both ligands was cubilin dependent during the early rodent gestation. In conclusion, the early cubilin expression and its function in protein and cholesterol uptake suggest an important role for cubilin in the development of the peri-implantation embryo.
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Affiliation(s)
- Emeline Assémat
- Inserm, UMR 538, Faculté de Médecine Saint-Antoine, Paris, France
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26
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Thomas FC, Sheth B, Eckert JJ, Bazzoni G, Dejana E, Fleming TP. Contribution of JAM-1 to epithelial differentiation and tight-junction biogenesis in the mouse preimplantation embryo. J Cell Sci 2004; 117:5599-608. [PMID: 15494378 DOI: 10.1242/jcs.01424] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We have investigated the contribution of the tight junction (TJ) transmembrane protein junction-adhesion-molecule 1 (JAM-1) to trophectoderm epithelial differentiation in the mouse embryo. JAM-1-encoding mRNA is expressed early from the embryonic genome and is detectable as protein from the eight-cell stage. Immunofluorescence confocal analysis of staged embryos and synchronized cell clusters revealed JAM-1 recruitment to cell contact sites occurred predominantly during the first hour after division to the eight-cell stage, earlier than any other TJ protein analysed to date in this model and before E-cadherin adhesion and cell polarization. During embryo compaction later in the fourth cell cycle, JAM-1 localized transiently yet precisely to the apical microvillous pole, where protein kinase Cζ (PKCζ) and PKCδ are also found, indicating a role in cell surface reorganization and polarization. Subsequently, in morulae and blastocysts, JAM-1 is distributed ubiquitously at cell contact sites within the embryo but is concentrated within the trophectoderm apicolateral junctional complex, a pattern resembling that of E-cadherin and nectin-2. However, treatment of embryos with anti-JAM-1-neutralizing antibodies indicated that JAM-1 did not contribute to global embryo compaction and adhesion but rather regulated the timing of blastocoel cavity formation dependent upon establishment of the trophectoderm TJ paracellular seal.
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Affiliation(s)
- Fay C Thomas
- School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton, SO16 7PX, UK
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27
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Mruk DD, Cheng CY. Sertoli-Sertoli and Sertoli-germ cell interactions and their significance in germ cell movement in the seminiferous epithelium during spermatogenesis. Endocr Rev 2004; 25:747-806. [PMID: 15466940 DOI: 10.1210/er.2003-0022] [Citation(s) in RCA: 614] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Spermatogenesis is the process by which a single spermatogonium develops into 256 spermatozoa, one of which will fertilize the ovum. Since the 1950s when the stages of the epithelial cycle were first described, reproductive biologists have been in pursuit of one question: How can a spermatogonium traverse the epithelium, while at the same time differentiating into elongate spermatids that remain attached to the Sertoli cell throughout their development? Although it was generally agreed upon that junction restructuring was involved, at that time the types of junctions present in the testis were not even discerned. Today, it is known that tight, anchoring, and gap junctions are found in the testis. The testis also has two unique anchoring junction types, the ectoplasmic specialization and tubulobulbar complex. However, attention has recently shifted on identifying the regulatory molecules that "open" and "close" junctions, because this information will be useful in elucidating the mechanism of germ cell movement. For instance, cytokines have been shown to induce Sertoli cell tight junction disassembly by shutting down the production of tight junction proteins. Other factors such as proteases, protease inhibitors, GTPases, kinases, and phosphatases also come into play. In this review, we focus on this cellular phenomenon, recapping recent developments in the field.
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Affiliation(s)
- Dolores D Mruk
- Population Council, Center for Biomedical Research, New York, New York 10021, USA.
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28
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Eckert JJ, McCallum A, Mears A, Rumsby MG, Cameron IT, Fleming TP. Specific PKC isoforms regulate blastocoel formation during mouse preimplantation development. Dev Biol 2004; 274:384-401. [PMID: 15385166 DOI: 10.1016/j.ydbio.2004.07.027] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Revised: 07/22/2004] [Accepted: 07/28/2004] [Indexed: 12/21/2022]
Abstract
During early mammalian development, blastocyst morphogenesis is achieved by epithelial differentiation of trophectoderm (TE) and its segregation from the inner cell mass (ICM). Two major interrelated features of TE differentiation required for blastocoel formation include intercellular junction biogenesis and a directed ion transport system, mediated by Na+/K+ ATPase. We have examined the relative contribution of intercellular signalling mediated by protein kinase C (PKC) and gap junctional communication in TE differentiation and blastocyst cavitation. The distribution pattern of four (delta, theta, iota/lambda, zeta) PKC isoforms and PKCmicro/PKD1 showed partial colocalisation with the tight junction marker ZO-1alpha+ in TE and all four PKCs (delta, theta, iota/lambda, zeta) showed distinct TE/ICM staining patterns (predominantly at the cell membrane within the TE and cytoplasmic within the ICM), indicating their potential contribution to TE differentiation and blastocyst morphogenesis. Specific inhibition of PKCdelta and zeta activity significantly delayed blastocyst formation. Although modulation of these PKC isoforms failed to influence the already established programme of epithelial junctional differentiation within the TE, Na+/K+ ATPase alpha1 subunit was internalised from membrane to cytoplasm. Inhibition of gap junctional communication, in contrast, had no influence on any of these processes. Our results demonstrate for the first time that distinct PKC isotypes contribute to the regulation of cavitation in preimplantation embryos via target proteins including Na+/K+ ATPase.
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Affiliation(s)
- Judith J Eckert
- Division of Cell Sciences, School of Biological Sciences, University of Southampton, Southampton SO16 7PX, UK.
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29
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Abstract
During the past decade, enormous advances have been made in cell biology. Major advances included the publication of the human genome sequence, the development of proteomics, and DNA microarray technologies and techniques to selectively "silence" genes using short strands of double-stranded RNA. Some areas of great progress that are particularly relevant to critical care medicine include huge improvements in our understanding of the signal transduction pathways involved in the innate immune response and adaptation to hypoxia. Other areas of important progress include improvements in our understanding of how inflammation causes derangements in epithelial structure and function and impairs cellular utilization of oxygen.
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Affiliation(s)
- Mitchell P Fink
- Departments of Critical Care Medicine and Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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30
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Eckert JJ, McCallum A, Mears A, Rumsby MG, Cameron IT, Fleming TP. PKC signalling regulates tight junction membrane assembly in the pre-implantation mouse embryo. Reproduction 2004; 127:653-67. [PMID: 15175502 DOI: 10.1530/rep.1.00150] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Epithelial differentiation including tight junction (TJ) formation occurs exclusively within the trophectoderm (TE) lineage of the mouse blastocyst. Here we examine mechanisms by which TJ protein membrane assembly might be regulated by protein kinase C (PKC) in the embryo. To overcome the inherent staging asynchrony of individual blastomeres within intact embryos, we have used isolated inner cell masses (ICMs) from early blastocysts to induce epithelial differentiation in their outer cells responding to their new cell contact pattern. Two TJ proteins examined retain their order of membrane assembly in isolated ICMs in culture as during normal development (early-assembling ZO-2 and late-assembling ZO-1α+), but this process is highly accelerated. Using six chemical modulators of PKC activity, we show here that PKC signalling is involved in the regulation of TJ membrane assembly. While indolactam-mediated PKC activation stimulates membrane assembly of both TJ proteins, TPA-mediated PKC activation stimulates only that of ZO-1α+. The PKC inhibitors Ro-31-8220, Ro-31-8425 and Gö 6983 suppress the stimulatory effect of both PKC activators on membrane assembly to varying extents according to inhibitor and TJ protein examined. Gö 6983 similarly inhibits ZO-2 and ZO-1α+membrane assembly. PKC inhibition by Gö 6976 appeared to stimulate TJ membrane assembly. Despite the broad PKC isotype specificity of the inhibitors used, these data suggest that the two TJ proteins are differently regulated by PKC isotypes or subfamilies. As Gö 6983 uniquely affects aPKC (particularly PKCζ) and we find that both PKCδ and ζ relocate upon activator treatment to colocalise partially with the TJ proteins in isolated ICMs, we suggest that at least PKCδ and ζ may play a central role in regulating TJ membrane assembly.
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Affiliation(s)
- Judith J Eckert
- University of Southampton, Division of Cell Sciences, School of Biological Sciences, Bassett Crescent East, Southampton SO16 7PX, UK.
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31
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Hamatani T, Carter MG, Sharov AA, Ko MSH. Dynamics of global gene expression changes during mouse preimplantation development. Dev Cell 2004; 6:117-31. [PMID: 14723852 DOI: 10.1016/s1534-5807(03)00373-3] [Citation(s) in RCA: 668] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Understanding preimplantation development is important both for basic reproductive biology and for practical applications including regenerative medicine and livestock breeding. Global expression profiles revealed and characterized the distinctive patterns of maternal RNA degradation and zygotic gene activation, including two major transient waves of de novo transcription. The first wave corresponds to zygotic genome activation (ZGA); the second wave, named mid-preimplantation gene activation (MGA), precedes the dynamic morphological and functional changes from the morula to blastocyst stage. Further expression profiling of embryos treated with inhibitors of transcription, translation, and DNA replication revealed that the translation of maternal RNAs is required for the initiation of ZGA. We propose a cascade of gene activation from maternal RNA/protein sets to ZGA gene sets and thence to MGA gene sets. The large number of genes identified as involved in each phase is a first step toward analysis of the complex gene regulatory networks.
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Affiliation(s)
- Toshio Hamatani
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, 333 Cassell Drive, Suite 3000, Baltimore, MD 21224, USA
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32
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Fleming TP, Wilkins A, Mears A, Miller DJ, Thomas F, Ghassemifar MR, Fesenko I, Sheth B, Kwong WY, Eckert JJ. Society for Reproductive Biology Founders' Lecture 2003.The making of an embryo: short-term goals and long-term implications. Reprod Fertil Dev 2004. [DOI: 10.1071/rd03070] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
During early development, the eutherian mammalian embryo forms a blastocyst comprising an outer trophectoderm epithelium and enclosed inner cell mass (ICM). The short-term goal of blastocyst morphogenesis, including epithelial differentiation and segregation of the ICM, is mainly regulated autonomously and comprises a combination of temporally controlled gene expression, cell polarisation, differentiative cell divisions and cell–cell interactions. This aspect of blastocyst biogenesis is reviewed, focusing, in particular, on the maturation and role of cell adhesion systems. Early embryos are also sensitive to their environment, which can affect their developmental potential in diverse ways and may lead to long-term consequences relating to fetal or postnatal growth and physiology. Some current concepts of embryo–environment interactions, which may impact on future health, are also reviewed.
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33
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Miller DJ, Eckert JJ, Lazzari G, Duranthon-Richoux V, Sreenan J, Morris D, Galli C, Renard JP, Fleming TP. Tight junction messenger RNA expression levels in bovine embryos are dependent upon the ability to compact and in vitro culture methods. Biol Reprod 2003; 68:1394-402. [PMID: 12606485 DOI: 10.1095/biolreprod.102.009951] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
We have established a transcription map of individual bovine embryos using semiquantitative reverse transcriptase-polymerase chain reaction to detect the levels of six marker genes involved in early embryo differentiation. The critical step of compaction during preimplantation development is often not accomplished or it takes place for only a short period in in vitro generated embryos, which may result in reduced viability. Compaction is accompanied by the assembly of intercellular tight junctions (TJs) as a barrier against the extraembryonic environment and as a prerequisite for blastocele formation. In the present study, we have related the expression of TJ gene mRNA in individual bovine embryos to their developmental stage, their competence to undergo a clear period of compaction before blastocyst formation, and their in vitro or in vivo origin. Our results indicate that embryos that showed a detectable and well-formed compaction period in vitro are of similar quality to their in vivo counterparts. Starting from the same amount of maternal message, in vivo and in vitro development differ most during the critical period of the major switch from maternal to embryonic genomic control before a dramatic increase of TJ mRNAs occurs upon blastocyst formation. Failure to compact in vitro results in significant reduction of specific transcript levels, in a manner that depends on culture conditions, which may contribute to reduced viability. We conclude that TJ mRNA expression levels are sensitive to environmental conditions that may influence the developmental potential of bovine blastocysts.
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Affiliation(s)
- Daniel J Miller
- Division of Cell Sciences, School of Biological Sciences, University of Southampton, Southampton SO16 7PX, United Kingdom
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Benais-Pont G, Punn A, Flores-Maldonado C, Eckert J, Raposo G, Fleming TP, Cereijido M, Balda MS, Matter K. Identification of a tight junction-associated guanine nucleotide exchange factor that activates Rho and regulates paracellular permeability. J Cell Biol 2003; 160:729-40. [PMID: 12604587 PMCID: PMC2173357 DOI: 10.1083/jcb.200211047] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rho family GTPases are important regulators of epithelial tight junctions (TJs); however, little is known about how the GTPases themselves are controlled during TJ assembly and function. We have identified and cloned a canine guanine nucleotide exchange factor (GEF) of the Dbl family of proto-oncogenes that activates Rho and associates with TJs. Based on sequence similarity searches and immunological and functional data, this protein is the canine homologue of human GEF-H1 and mouse Lfc, two previously identified Rho-specific exchange factors known to associate with microtubules in nonpolarized cells. In agreement with these observations, immunofluorescence of proliferating MDCK cells revealed that the endogenous canine GEF-H1/Lfc associates with mitotic spindles. Functional analysis based on overexpression and RNA interference in polarized MDCK cells revealed that this exchange factor for Rho regulates paracellular permeability of small hydrophilic tracers. Although overexpression resulted in increased size-selective paracellular permeability, such cell lines exhibited a normal overall morphology and formed fully assembled TJs as determined by measuring transepithelial resistance and by immunofluorescence and freeze-fracture analysis. These data indicate that GEF-H1/Lfc is a component of TJs and functions in the regulation of epithelial permeability.
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Affiliation(s)
- Gaelle Benais-Pont
- Department of Cell Biology, University of Geneva, 1211 Geneva, Switzerland
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González-Mariscal L, Betanzos A, Nava P, Jaramillo BE. Tight junction proteins. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2003; 81:1-44. [PMID: 12475568 DOI: 10.1016/s0079-6107(02)00037-8] [Citation(s) in RCA: 810] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A fundamental function of epithelia and endothelia is to separate different compartments within the organism and to regulate the exchange of substances between them. The tight junction (TJ) constitutes the barrier both to the passage of ions and molecules through the paracellular pathway and to the movement of proteins and lipids between the apical and the basolateral domains of the plasma membrane. In recent years more than 40 different proteins have been discovered to be located at the TJs of epithelia, endothelia and myelinated cells. This unprecedented expansion of information has changed our view of TJs from merely a paracellular barrier to a complex structure involved in signaling cascades that control cell growth and differentiation. Both cortical and transmembrane proteins integrate TJs. Among the former are scaffolding proteins containing PDZ domains, tumor suppressors, transcription factors and proteins involved in vesicle transport. To date two components of the TJ filaments have been identified: occludin and claudin. The latter is a protein family with more than 20 members. Both occludin and claudins are integral proteins capable of interacting adhesively with complementary molecules on adjacent cells and of co-polymerizing laterally. These advancements in the knowledge of the molecular structure of TJ support previous physiological models that exhibited TJ as dynamic structures that present distinct permeability and morphological characteristics in different tissues and in response to changing natural, pathological or experimental conditions.
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Affiliation(s)
- L González-Mariscal
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies (CINVESTAV), Ave. Politécnico Nacional 2508, México DF, 07000, Mexico.
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36
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Affiliation(s)
- C M Warner
- Department of Biology, Northeastern University, Boston, Massachusetts 02115, USA
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Andreeva AY, Krause E, Müller EC, Blasig IE, Utepbergenov DI. Protein kinase C regulates the phosphorylation and cellular localization of occludin. J Biol Chem 2001; 276:38480-6. [PMID: 11502742 DOI: 10.1074/jbc.m104923200] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Occludin is an integral membrane phosphoprotein specifically associated with tight junctions, contributing to the structure and function of this intercellular seal. Occludin function is thought to be regulated by phosphorylation, but no information is available on the molecular pathways involved. In the present study, the involvement of the protein kinase C pathway in the regulation of the phosphorylation and cellular distribution of occludin has been investigated. Phorbol 12-myristate 13-acetate and 1,2-dioctanoylglycerol induced the rapid phosphorylation of occludin in Madin-Darby canine kidney cells cultured in low extracellular calcium medium with a concomitant translocation of occludin to the regions of cell-cell contact. The extent of occludin phosphorylation as well as its incorporation into tight junctions induced by protein kinase C activators or calcium switch were markedly decreased by the protein kinase C inhibitor GF-109203X. In addition, in vitro experiments showed that the recombinant COOH-terminal domain of murine occludin could be phosphorylated by purified protein kinase C. Ser(338) of occludin was identified as an in vitro protein kinase C phosphorylation site using peptide mass fingerprint analysis and electrospray ionization tandem mass spectroscopy. These findings indicate that protein kinase C is involved in the regulation of occludin function at tight junctions.
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Affiliation(s)
- A Y Andreeva
- Forschungsinstitut für Molekulare Pharmakologie, 13125 Berlin-Buch and Charité, Humboldt Universität Berlin, 13092 Berlin, Germany
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38
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Abstract
Embryonic development begins with cleavage of the fertilized egg. Cleavage comprises two major processes: cytokinesis and formation of a polarized epithelial cell layer. The focus of this review is comparison of the generation of membrane polarity during embryonic cleavage in three different developmental model systems. In mammalian embryos, as exemplified by analysis of the mouse, generation of distinct membrane domains is uncoupled from cleavage divisions and is initiated in a specific developmental phase, called compaction. In Xenopus laevis embryos, generation of polarized blastomeres occurs simultaneously with cytokinesis. The origin of specific membrane domains of X. laevis polar blastomeres, however, can be traced back to oogenesis. Finally, in Drosophila melanogaster, generation of polarized cells occurs at cellularization. The relevance of cell adhesion, cell junctions and cytocortical scaffolds will be discussed for each of the model systems. Despite enormous morphologic differences, the three models share many common features; in particular, many important molecular interactions are conserved.
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Affiliation(s)
- H A Müller
- Heinrich Heine Universität Düsseldorf, Institut für Genetik, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
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Brizuela BJ, Wessely O, De Robertis EM. Overexpression of the Xenopus tight-junction protein claudin causes randomization of the left-right body axis. Dev Biol 2001; 230:217-29. [PMID: 11161574 DOI: 10.1006/dbio.2000.0116] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study presents Xenopus claudin (Xcla), a tight-junction protein that is abundantly expressed in eggs and neuroectodermal precursors during early development. It was isolated via a differential screen for mRNAs enriched in microsomes in the Xenopus blastula. The Xcla protein contains four transmembrane domains and a carboxy-terminal cytoplasmic region with a putative PDZ-binding site. We show that this PDZ-binding site of Xcla is critical for its correct localization on the cell membrane and that a truncated form leads to delocalization of the tight-junction protein ZO-1. Overexpression of Xcla causes changes in the cell adhesion properties of blastomeres and leads to visceral situs randomization. The results suggest that left-right axial patterning is very sensitive to changes in regulation of cell-cell interactions and implicate a tight-junction protein in the determination of left-right asymmetry.
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Affiliation(s)
- B J Brizuela
- Howard Hughes Medical Institute and Department of Biological Chemistry, University of California at Los Angeles, Los Angeles, California, 90095-1662, USA
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Kubota H, Chiba H, Takakuwa Y, Osanai M, Tobioka H, Kohama G, Mori M, Sawada N. Retinoid X receptor alpha and retinoic acid receptor gamma mediate expression of genes encoding tight-junction proteins and barrier function in F9 cells during visceral endodermal differentiation. Exp Cell Res 2001; 263:163-72. [PMID: 11161715 DOI: 10.1006/excr.2000.5113] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Retinoids are critical for differentiation of columnar epithelial cells and for preventing metaplasia of these cells into stratified squamous epithelial cells, in which tight junctions (TJs) are essentially absent. This implies that retinoids might play important roles in regulating the structures and functions of TJs of columnar epithelium. F9 murine embryonal carcinoma cells differentiate into epithelial cells resembling visceral endoderm bearing TJs, when grown in suspension as aggregates in the presence of retinoic acid (RA). We show that RA induces the TJ structure and expression of several TJ-associated molecules, such as ZO-1, occludin, claudin-6, and claudin-7, as well as a barrier function in the genetically engineered cell line F9:rtTA:Cre-ER(T) L32T2, which allows sophisticated genetic manipulations simply by addition of ligands (H. Chiba et al., 2000, Exp. Cell Res. 260, 334-339). Interestingly, our data indicate that a barrier for small substances is generated after that for large ones during de novo formation of TJs. We also compared the RA-induced expression of TJ components and barrier function in RXRalpha(-/-)-RARgamma(-/-) F9 cells with those in wild-type cells and show that the retinoid signals for transduction of these events are mediated by specific RXR-RAR pairs.
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Affiliation(s)
- H Kubota
- Department of Pathology, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Japan
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Sheth B, Fontaine JJ, Ponza E, McCallum A, Page A, Citi S, Louvard D, Zahraoui A, Fleming TP. Differentiation of the epithelial apical junctional complex during mouse preimplantation development: a role for rab13 in the early maturation of the tight junction. Mech Dev 2000; 97:93-104. [PMID: 11025210 DOI: 10.1016/s0925-4773(00)00416-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We have investigated the mechanisms by which the epithelial apicolateral junctional complex (AJC) is generated during trophectoderm differentiation in the mouse blastocyst using molecular, structural and functional analyses. The mature AJC comprises an apical tight junction (TJ), responsible for intercellular sealing and blastocoel formation, and subjacent zonula adherens E-cadherin/catenin adhesion complex which also extends along lateral membrane contact sites. Dual labelling confocal microscopy revealed that the AJC derived from a single 'intermediate' complex formed following embryo compaction at the 8-cell stage in which the TJ-associated peripheral membrane protein, ZO-1alpha- isoform, was co-localized with both alpha- and beta-catenin. However, following assembly of the TJ transmembrane protein, occludin, from the early 32-cell stage when blastocoel formation begins, ZO-1alpha- and other TJ proteins (ZO-1alpha+ isoform, occludin, cingulin) co-localized in an apical TJ which was separate from a subjacent E-cadherin/catenin zonula adherens complex. Thin-section electron microscopy confirmed that a single zonula adherens-like junctional complex present at the AJC site following compaction matured into a dual TJ and zonula adherens complex at the blastocyst stage. Embryo incubation in the tracer FITC-dextran 4 kDa showed that a functional TJ seal was established coincident with blastocoel formation. We also found that rab13, a small GTPase previously localized to the TJ, is expressed at all stages of preimplantation development and relocates from the cytoplasm to the site of AJC biogenesis from compaction onwards with rab13 and ZO-1alpha- co-localizing precisely. Our data indicate that the segregation of the two elements of the AJC occurs late in trophectoderm differentiation and likely has functional importance in blastocyst formation. Moreover, we propose a role for rab13 in the specification of the AJC site and the formation and segregation of the TJ.
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Affiliation(s)
- B Sheth
- Division of Cell Sciences, School of Biological Sciences, University of Southampton, Bassett Crescent East, SO16 7PX, Southampton, UK
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Fesenko I, Kurth T, Sheth B, Fleming TP, Citi S, Hausen P. Tight junction biogenesis in the early Xenopus embryo. Mech Dev 2000; 96:51-65. [PMID: 10940624 DOI: 10.1016/s0925-4773(00)00368-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tight junctions (TJs) perform a critical role in the transport functions and morphogenetic activity of the primary epithelium formed during Xenopus cleavage. Biogenesis of these junctions was studied by immunolocalization of TJ-associated proteins (cingulin, ZO-1 and occludin) and by an in vivo biotin diffusion assay. Using fertilized eggs synchronized during the first division cycle, we found that membrane assembly of the TJ initiated at the animal pole towards the end of zygote cytokinesis and involved sequential incorporation of components in the order cingulin, ZO-1 and occludin. The three constituents appeared to be recruited from maternal stores and were targeted to the nascent TJ site by different pathways. TJ protein assembly was focused precisely to the border between the oolemma-derived apical membrane and newly-inserted basolateral membrane generated during cytokinesis and culminated in the formation of functional TJs in the two-cell embryo, which maintained a diffusion barrier. New membrane formation and the generation of cell surface polarity therefore precede initiation of TJ formation. Moreover, assembly of TJ marker protein precisely at the apical-basolateral membrane boundary was preserved in the complete absence of intercellular contacts and adhesion. Thus, the mechanism of TJ biogenesis in the Xenopus early embryo relies on intrinsic cues of a cell autonomous mechanism. These data reveal a distinction between Xenopus and mammalian early embryos in the origin and mechanisms of epithelial cell polarization and TJ formation during cleavage of the egg.
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Affiliation(s)
- I Fesenko
- Max-Planck-Institute for Developmental Biology, Spemannstrasse 35, D-72076, Tübingen, Germany
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Fleming TP, Papenbrock T, Fesenko I, Hausen P, Sheth B. Assembly of tight junctions during early vertebrate development. Semin Cell Dev Biol 2000; 11:291-9. [PMID: 10966863 DOI: 10.1006/scdb.2000.0179] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Tight junction formation during development is critical for embryonic patterning and organization. We consider mechanisms of junction biogenesis in cleaving mouse and Xenopus eggs. Junction assembly follows the establishment of cell polarity at 8-cell (mouse) or 2-cell (Xenopus) stages, characterized by sequential membrane delivery of constituents, coordinated by embryonic (mouse) or maternal (Xenopus) expression programmes. Cadherin adhesion is permissive for tight junction construction only in the mouse. Occludin post-translational modification and membrane delivery, mediated by delayed ZO-1 alpha(+)isoform expression in the mouse, provides a mechanism for completion of tight junction biogenesis and sealing, regulating the timing of blastocoel cavitation.
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Affiliation(s)
- T P Fleming
- Division of Cell Sciences, School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK.
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