101
|
Kuure S, Cebrian C, Machingo Q, Lu BC, Chi X, Hyink D, D'Agati V, Gurniak C, Witke W, Costantini F. Actin depolymerizing factors cofilin1 and destrin are required for ureteric bud branching morphogenesis. PLoS Genet 2010; 6:e1001176. [PMID: 21060807 PMCID: PMC2965756 DOI: 10.1371/journal.pgen.1001176] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 09/22/2010] [Indexed: 01/10/2023] Open
Abstract
The actin depolymerizing factors (ADFs) play important roles in several cellular processes that require cytoskeletal rearrangements, such as cell migration, but little is known about the in vivo functions of ADFs in developmental events like branching morphogenesis. While the molecular control of ureteric bud (UB) branching during kidney development has been extensively studied, the detailed cellular events underlying this process remain poorly understood. To gain insight into the role of actin cytoskeletal dynamics during renal branching morphogenesis, we studied the functional requirements for the closely related ADFs cofilin1 (Cfl1) and destrin (Dstn) during mouse development. Either deletion of Cfl1 in UB epithelium or an inactivating mutation in Dstn has no effect on renal morphogenesis, but simultaneous lack of both genes arrests branching morphogenesis at an early stage, revealing considerable functional overlap between cofilin1 and destrin. Lack of Cfl1 and Dstn in the UB causes accumulation of filamentous actin, disruption of normal epithelial organization, and defects in cell migration. Animals with less severe combinations of mutant Cfl1 and Dstn alleles, which retain one wild-type Cfl1 or Dstn allele, display abnormalities including ureter duplication, renal hypoplasia, and abnormal kidney shape. The results indicate that ADF activity, provided by either cofilin1 or destrin, is essential in UB epithelial cells for normal growth and branching. Development of the ureter and collecting ducts of the kidney requires extensive growth and branching of an epithelial tube, the ureteric bud. While many genes that control this process are known, the cellular events that underlie renal morphogenesis remain poorly understood. Many cellular changes that might contribute to ureteric bud morphogenesis, such as migration and changes in shape, involve the actin cytoskeleton. Actin depolymerizing factors (ADFs) are important for changes in the organization of the cytoskeleton in cultured cells, but the roles of the ADF genes in vivo remain to be fully elucidated. Here, we examine the importance of the ADFs cofilin1 and destrin in ureteric bud branching and find that lack of both genes arrests this process at an early stage, while lesser reductions in ADF gene dosage cause more subtle defects in kidney development. This finding may help us to understand the origins of certain congenital malformations in humans.
Collapse
Affiliation(s)
- Satu Kuure
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Cristina Cebrian
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Quentin Machingo
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Benson C. Lu
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Xuan Chi
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Deborah Hyink
- Department of Medicine, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Vivette D'Agati
- Department of Pathology, Columbia University Medical Center, New York, New York, United States of America
| | | | - Walter Witke
- Institute of Genetics, University of Bonn, Bonn, Germany
| | - Frank Costantini
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
102
|
Knox S, Lombaert I, Reed X, Vitale-Cross L, Gutkind J, Hoffman M. Parasympathetic innervation maintains epithelial progenitor cells during salivary organogenesis. Science 2010; 329:1645-7. [PMID: 20929848 PMCID: PMC3376907 DOI: 10.1126/science.1192046] [Citation(s) in RCA: 235] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The maintenance of a progenitor cell population as a reservoir of undifferentiated cells is required for organ development and regeneration. However, the mechanisms by which epithelial progenitor cells are maintained during organogenesis are poorly understood. We report that removal of the parasympathetic ganglion in mouse explant organ culture decreased the number and morphogenesis of keratin 5-positive epithelial progenitor cells. These effects were rescued with an acetylcholine analog. We demonstrate that acetylcholine signaling, via the muscarinic M1 receptor and epidermal growth factor receptor, increased epithelial morphogenesis and proliferation of the keratin 5-positive progenitor cells. Parasympathetic innervation maintained the epithelial progenitor cell population in an undifferentiated state, which was required for organogenesis. This mechanism for epithelial progenitor cell maintenance may be targeted for organ repair or regeneration.
Collapse
Affiliation(s)
| | | | - X. Reed
- Matrix and Morphogenesis Unit, LCDB
| | - L Vitale-Cross
- OPCB, NIDCR, NIH, 30 Convent Dr, Bethesda, MD 20892, USA
| | - J.S. Gutkind
- OPCB, NIDCR, NIH, 30 Convent Dr, Bethesda, MD 20892, USA
| | | |
Collapse
|
103
|
Abstract
The developmental origin of vaginal epithelium has been controversial for nearly a century, with speculation that vaginal epithelium originates from the Müllerian duct, Wolffian duct, and/or urogenital sinus. None of these possibilities have been definitively proven or disproven by direct scientific data. To define precisely the origin of vaginal epithelium, epithelial cells of the Müllerian duct, Wolffian duct, or urogenital sinus were fluorescently labeled in mouse embryos by crossing tdTomato-EGFP dual-reporter transgenic mice with transgenic mouse lines that express Cre-recombinase in each type of epithelium. In embryos and newborn mice, the vagina consisted of fused Müllerian ducts plus the sinus vagina of urogenital sinus origin. However, the proportion of the sinus vagina was significantly reduced as the Müllerian vagina grew caudally. By postpartum day 7, the Müllerian vagina extended to the caudal end of the body, whereas the sinus vagina remained only at the junction between the vagina and perineal skin. As the vagina opened in puberty, urogenital sinus epithelium was detected only in the vulva, but not in the vagina. Additionally, from embryo to adult stages, residual Wolffian duct epithelium was present in the dorsolateral stromal wall of the vagina, but not within vaginal or vulvar epithelium. In conclusion, adult mouse vaginal epithelium is derived solely from Müllerian duct epithelium.
Collapse
Affiliation(s)
- Takeshi Kurita
- Division of Reproductive Biology Research, Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Lurie 7-117, 303 East Superior Street, Chicago, IL 60611, USA.
| |
Collapse
|
104
|
Paiva KBS, Silva-Valenzuela MDG, Massironi SMG, Ko GM, Siqueira FM, Nunes FD. Differential Shh, Bmp and Wnt gene expressions during craniofacial development in mice. Acta Histochem 2010; 112:508-17. [PMID: 19608221 DOI: 10.1016/j.acthis.2009.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 05/05/2009] [Accepted: 05/19/2009] [Indexed: 01/22/2023]
Abstract
In this study, Bmp-4, Wnt-5a and Shh gene expressions were compared during early craniofacial development in mice by comparative non-isotopic in situ hybridization. Wild-type C57BL/6J mice were studied at various stages of embryonic development (from 8.5- to 13.5-day-old embryos--E8.5-13.5). During early odontogenesis, transcripts for Bmp-4, Shh and Wnt-5a were co-localised at the tooth initiation stage. At E8.5, Shh mRNA expression was restricted to diencephalon and pharyngeal endoderm. Before maxillae and mandible ossification, Bmp-4 and Wnt-5a signals were detected in the mesenchymal cells and around Meckel's cartilage. During palatogenesis, Shh was expressed only in the epithelium and Wnt-5a only in the mesenchyme of the elevating palatal shelves. During tongue development, Shh expression was found in mesenchyme, probably contributing to tongue miogenesis, while Wnt-5a signal was in the epithelium, possibly during placode development and papillae formation. Taken together, these findings suggest that Bmp-4, Shh and Wnt-5a gene expressions may act together on the epithelial-mesenchymal interactions occurring in several aspects of the early mouse craniofacial development, such as odontogenesis, neuronal development, maxillae and mandible ossification, palatogenesis and tongue formation.
Collapse
|
105
|
Cao H, Wang J, Li X, Florez S, Huang Z, Venugopalan S, Elangovan S, Skobe Z, Margolis H, Martin J, Amendt B. MicroRNAs play a critical role in tooth development. J Dent Res 2010; 89:779-84. [PMID: 20505045 PMCID: PMC3014323 DOI: 10.1177/0022034510369304] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 03/12/2010] [Accepted: 03/15/2010] [Indexed: 11/17/2022] Open
Abstract
MicroRNAs are known to regulate gene function in many tissues and organs, but their expression and function, if any, in tooth development are elusive. We sought to identify them by microRNA screening analyses and reveal their overall roles by inactivating Dicer1 in the dental epithelium and mesenchyme. Discrete sets of microRNAs are expressed in molars compared with incisors as well as epithelium compared with mesenchyme. Conditional knockout (cKO) of Dicer1 (mature microRNAs) in the dental epithelium of the Pitx2-Cre mouse results in multiple and branched enamel-free incisors and cuspless molars, and change in incisor patterning and in incisor and molar size and shape. Analyses of differentiating dental epithelial markers reveal a defect in ameloblast differentiation. Conversely, the cervical loop (stem cell niche) is expanded in Dicer1 cKO. These results demonstrate that tooth development is tightly controlled by microRNAs and that specific microRNAs regulate tooth epithelial stem cell differentiation.
Collapse
Affiliation(s)
- H. Cao
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| | - J. Wang
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| | - X. Li
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| | - S. Florez
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| | - Z. Huang
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| | - S.R. Venugopalan
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| | - S. Elangovan
- Department of Biomineralization, The Forsyth Institute, Boston, MA, USA
| | - Z. Skobe
- Department of Biomineralization, The Forsyth Institute, Boston, MA, USA
| | - H.C. Margolis
- Department of Biomineralization, The Forsyth Institute, Boston, MA, USA
| | - J.F. Martin
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| | - B.A. Amendt
- Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
| |
Collapse
|
106
|
Gao S, Wu H, Wang F, Wang Z. Altered differentiation and proliferation of prostate epithelium in mice lacking the androgen receptor cofactor p44/WDR77. Endocrinology 2010; 151:3941-53. [PMID: 20519372 PMCID: PMC2940529 DOI: 10.1210/en.2009-1080] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 04/26/2010] [Indexed: 11/19/2022]
Abstract
Although it has been observed that various cofactors modulate activity of the androgen receptor (AR), the specific relationship between AR cofactors and prostate development and functions has not been well studied. To determine whether AR cofactor p44/WDR77 is important in prostate growth and development, we examined prostate architecture in p44/WDR77-null mice and wild-type (WT) littermates. Prostate glands from p44/WDR77-deficient animals were not only smaller than those from WT mice but also had fewer branches and terminal duct tips and were deficient in production of secretory proteins. The p44/WDR77-null prostate tissue was less differentiated and hyperproliferative relative to WT littermates. In addition, the altered expression of androgen-regulated genes was observed in the p44/WDR77-null prostate. Thus, these results suggest that the AR cofactor p44/WDR77 plays important roles in prostate growth and differentiation by modulating AR-target gene expression.
Collapse
Affiliation(s)
- Shen Gao
- Department of Cancer Biology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030-4009, USA
| | | | | | | |
Collapse
|
107
|
Yin A, Winata CL, Korzh S, Korzh V, Gong Z. Expression of components of Wnt and Hedgehog pathways in different tissue layers during lung development in Xenopus laevis. Gene Expr Patterns 2010; 10:338-44. [PMID: 20682360 DOI: 10.1016/j.gep.2010.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 07/21/2010] [Accepted: 07/24/2010] [Indexed: 11/19/2022]
Abstract
Although Wnt and Hedgehog (Hh) signaling pathways play important roles in mouse lung development, these have not been explored in the development of Xenopus lung. This may be due to the lack of specific molecular markers for different layers of tissue in Xenopus lung and/or insufficient knowledge on expression patterns of Wnt and Hh signaling components in Xenopus lung. In this study, we first described the early morphogenesis of Xenopus laevis lung by using surfactant protein C (sftpc) as a marker of lung epithelium and compared it with the expression patterns of several genes of Wnt and Hh pathways in Xenopus lungs. Our data showed that wnt7b was expressed in the entire lung epithelium from stage 37 to stage 45, while two other Wnt signaling components, wnt5a and wif1 (wnt inhibitory factor 1), were expressed in the mesenchyme layer of the entire lungs through stages 39-41. We also found that sonic hedgehog (shh) was expressed at stage 41 only in the anterior, but not in the posterior part of the lungs. These results show the expression of wnt5a, wnt7b, wif1 and shh in different layers of tissue of Xenopus lungs at early developmental stages, which implies different roles of these genes in the early development of Xenopus lungs. Our study for the first time defined specific molecular markers for description of early lung development in Xenopus, as well as provided information about expression of components of Wnt and Hh pathways in early Xenopus lungs, which should be useful for future functional studies.
Collapse
Affiliation(s)
- Ao Yin
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | | | | | | | | |
Collapse
|
108
|
Evstifeeva AI, Kremnev SV, Belousov LV. [Changes in topology and geometry of the embryonic epithelium of Xenopus during relaxation of mechanical tension]. Ontogenez 2010; 41:190-198. [PMID: 20583626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The paper presents the results of statistical evaluation of the changes of cellular apex connections, apical angles, and apical indices of ventral cells of the epiectodermal gastrula of Xenopus during the first HC-four hours after the relaxation of mechanical tension. In the unrelaxed epithelium, an overwhelming majority of cells have three apical connections, apical angles close to 120 degrees, and apical indices around one (isodiametric cells); after relaxation, the number of cells with more than three connections, the number of apical angles deviating substantially from 120 degrees, and the percentage of columnar cells with high apical index increase. Apices with more than three connections tend to gather in enclosed groups, forming a smooth line of cell walls. The length and curvature of cell walls with four apical connections significantly exceeds those same indicators for cells with three apical connections. The observed changes in topology and geometry of cells correspond to reconstructions observed during normal morphogenesis. They are considered in terms of the hyper-restoration model of mechanical tension in relaxed epithelial layers.
Collapse
|
109
|
Campana M, Maury B, Dutreix M, Peyriéras N, Sarti A. Methods toward in vivo measurement of zebrafish epithelial and deep cell proliferation. Comput Methods Programs Biomed 2010; 98:103-117. [PMID: 19781805 DOI: 10.1016/j.cmpb.2009.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/23/2009] [Accepted: 08/24/2009] [Indexed: 05/28/2023]
Abstract
We present a strategy for automatic classification and density estimation of epithelial enveloping layer (EVL) and deep layer (DEL) cells, throughout zebrafish early embryonic stages. Automatic cells classification provides the bases to measure the variability of relevant parameters, such as cells density, in different classes of cells and is finalized to the estimation of effectiveness and selectivity of anticancer drug in vivo. We aim at approaching these measurements through epithelial/deep cells classification, epithelial area and thickness measurement, and density estimation from scattered points. Our procedure is based on Minimal Surfaces, Otsu clustering, Delaunay Triangulation, and Within-R cloud of points density estimation approaches. In this paper, we investigated whether the distance between nuclei and epithelial surface is sufficient to discriminate epithelial cells from deep cells. Comparisons of different density estimators, experimental results, and extensively accuracy measurements are included.
Collapse
Affiliation(s)
- Matteo Campana
- Department of Electronics, Computer Sciences and Systems, Bologna University, Bologna, Italy.
| | | | | | | | | |
Collapse
|
110
|
Abstract
OBJECTIVE Current studies indicate that Hedgehog (Hh) signaling must be excluded during early stages of pancreas formation. However, conflicting evidence suggests that Hh signaling may be active later during pancreas formation and that it is required for insulin production and secretion in cultured beta-cell lines. The objective of this study was to address these discrepancies by assessing the in vivo role of epithelial Hh signaling in the pancreas. RESEARCH DESIGN AND METHODS To identify Hh-active cells in the developing and adult pancreas epithelium, we characterized transgenic reporter Patched1-LacZ mice. To determine the requirement for epithelial Hh signaling in the pancreas, we eliminated an essential Hh signaling component, Smoothened (Smo), in the pancreatic epithelium, and assessed pancreatic development and adult beta-cell physiology phenotypes. RESULTS Characterization of Patched1-LacZ reporter mice revealed low-level LacZ expression in pancreatic epithelial cells throughout development until birth, when LacZ activity increases in intensity specifically in endocrine and ductal cells. In the absence of Hh signaling, Smo-deficient mice have delayed pancreas formation leading to a temporary reduction in pancreatic epithelium and beta-cell numbers. Although beta-cell numbers recover by birth, adult Smo-deficient mice display glucose intolerance, increased insulin sensitivity, and reduced total insulin production. CONCLUSIONS These data show that Hh signaling functions early during pancreas morphogenesis to regulate epithelial and beta-cell expansion and to modulate glucose metabolism by regulating insulin production in adult mice.
Collapse
Affiliation(s)
- Janet Lau
- From the Diabetes Center, University of California, San Francisco, San Francisco, California
| | - Matthias Hebrok
- From the Diabetes Center, University of California, San Francisco, San Francisco, California
- Corresponding author: Matthias Hebrok,
| |
Collapse
|
111
|
Abstract
The transcription factor Sox9 has been implicated in inner ear formation in several species. To investigate the long-term consequences of Sox9 depletion on inner ear development we analyzed the inner ear architecture of Sox9-depleted Xenopus tadpoles generated by injection of increasing amounts of Sox9 morpholino antisense oligonucleotides. We found that Sox9-depletion resulted in major defects in the development of vestibular structures, semicircular canals and utricle, while the ventrally located saccule was less severely affected in these embryos. Consistent with this phenotype, we observed a specific loss of the dorsal expression of Wnt3a expression in the otic vesicle of Sox9 morphants, associated with an increase in cell death and a reduction in cell proliferation in the region of the presumptive otic epithelium. We propose that, in addition to its early role in placode specification, Sox9 is also required for the maintenance of progenitors in the otic epithelium.
Collapse
Affiliation(s)
- Byung-Yong Park
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Jean-Pierre Saint-Jeannet
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| |
Collapse
|
112
|
Shao W, Wu J, Chen J, Lee DM, Tishkina A, Harris TJC. A modifier screen for Bazooka/PAR-3 interacting genes in the Drosophila embryo epithelium. PLoS One 2010; 5:e9938. [PMID: 20368978 PMCID: PMC2848566 DOI: 10.1371/journal.pone.0009938] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 03/07/2010] [Indexed: 11/19/2022] Open
Abstract
Background The development and homeostasis of multicellular organisms depends on sheets of epithelial cells. Bazooka (Baz; PAR-3) localizes to the apical circumference of epithelial cells and is a key hub in the protein interaction network regulating epithelial structure. We sought to identify additional proteins that function with Baz to regulate epithelial structure in the Drosophila embryo. Methodology/Principal Findings The baz zygotic mutant cuticle phenotype could be dominantly enhanced by loss of known interaction partners. To identify additional enhancers, we screened molecularly defined chromosome 2 and 3 deficiencies. 37 deficiencies acted as strong dominant enhancers. Using deficiency mapping, bioinformatics, and available single gene mutations, we identified 17 interacting genes encoding known and predicted polarity, cytoskeletal, transmembrane, trafficking and signaling proteins. For each gene, their loss of function enhanced adherens junction defects in zygotic baz mutants during early embryogenesis. To further evaluate involvement in epithelial polarity, we generated GFP fusion proteins for 15 of the genes which had not been found to localize to the apical domain previously. We found that GFP fusion proteins for Drosophila ASAP, Arf79F, CG11210, Septin 5 and Sds22 could be recruited to the apical circumference of epithelial cells. Nine of the other proteins showed various intracellular distributions, and one was not detected. Conclusions/Significance Our enhancer screen identified 17 genes that function with Baz to regulate epithelial structure in the Drosophila embryo. Our secondary localization screen indicated that some of the proteins may affect epithelial cell polarity by acting at the apical cell cortex while others may act through intracellular processes. For 13 of the 17 genes, this is the first report of a link to baz or the regulation of epithelial structure.
Collapse
Affiliation(s)
- Wei Shao
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Johnny Wu
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jeyla Chen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Donghoon M. Lee
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Alisa Tishkina
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Tony J. C. Harris
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
| |
Collapse
|
113
|
Fritzsch B, Dillard M, Lavado A, Harvey NL, Jahan I. Canal cristae growth and fiber extension to the outer hair cells of the mouse ear require Prox1 activity. PLoS One 2010; 5:e9377. [PMID: 20186345 PMCID: PMC2826422 DOI: 10.1371/journal.pone.0009377] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 02/04/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The homeobox gene Prox1 is required for lens, retina, pancreas, liver, and lymphatic vasculature development and is expressed in inner ear supporting cells and neurons. METHODOLOGY/PRINCIPAL FINDINGS We have investigated the role of Prox1 in the developing mouse ear taking advantage of available standard and conditional Prox1 mutant mouse strains using Tg(Pax2-Cre) and Tg(Nes-Cre). A severe reduction in the size of the canal cristae but not of other vestibular organs or the cochlea was identified in the E18.5 Prox1(Flox/Flox); Tg(Pax2-Cre) mutant ear. In these mutant embryos, hair cell differentiated; however, their distribution pattern was slightly disorganized in the cochlea where the growth of type II nerve fibers to outer hair cells along Prox1 expressing supporting cells was severely disrupted. In the case of Nestin-Cre, we found that newborn Prox1(Flox/Flox); Tg(Nestin-Cre) exhibit only a disorganized innervation of outer hair cells despite apparently normal cellular differentiation of the organ of Corti, suggesting a cell-autonomous function of Prox1 in neurons. CONCLUSIONS/SIGNIFICANCE These results identify a dual role of Prox1 during inner ear development; growth of the canal cristae and fiber guidance of Type II fibers along supporting cells in the cochlea.
Collapse
MESH Headings
- Animals
- Animals, Newborn
- Cell Differentiation
- Cochlea/embryology
- Cochlea/metabolism
- Ear, Inner/embryology
- Ear, Inner/metabolism
- Ear, Inner/ultrastructure
- Embryo, Mammalian/embryology
- Embryo, Mammalian/metabolism
- Epithelium/embryology
- Epithelium/metabolism
- Female
- Gene Expression Regulation, Developmental
- Hair Cells, Auditory, Outer/metabolism
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Immunohistochemistry
- In Situ Hybridization
- Male
- Mice
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Microscopy, Electron, Transmission
- Mutation
- Pregnancy
- Time Factors
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/metabolism
- Vestibule, Labyrinth/embryology
- Vestibule, Labyrinth/metabolism
Collapse
Affiliation(s)
- Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America.
| | | | | | | | | |
Collapse
|
114
|
Nemolato S, Cabras T, Cau F, Fanari MU, Fanni D, Manconi B, Messana I, Castagnola M, Faa G. Different thymosin Beta 4 immunoreactivity in foetal and adult gastrointestinal tract. PLoS One 2010; 5:e9111. [PMID: 20161756 PMCID: PMC2817748 DOI: 10.1371/journal.pone.0009111] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Accepted: 01/12/2010] [Indexed: 02/06/2023] Open
Abstract
Background Thymosin beta 4 (Tβ4) is a member of beta-thymosins, a family of peptides that play essential roles in many cellular functions. A recent study from our group suggested a role for Tβ4 in the development of human salivary glands. The aim of this study was to analyze the expression of Tβ4 in the human gut during development, and in the adult. Methodology/Principal Findings Immunolocalization of Tβ4 was studied in autoptic samples of tongue, oesophagus, stomach, ileum, colon, liver and pancreas obtained from two human foetuses and two adults. Tβ4 appeared unevenly distributed, with marked differences between foetuses and adults. In the stomach, superficial epithelium was positive in foetuses and negative in adults. Ileal enterocytes were strongly positive in the adult and weakly positive in the foetuses. An increase in reactivity for Tβ4 was observed in superficial colon epithelium of adults as compared with the foetuses. Striking differences were found between foetal and adult liver: the former showed a very low reactivity for Tβ4 while in the adult we observed a strong reactivity in the vast majority of the hepatocytes. A peculiar pattern was found in the pancreas, with the strongest reactivity observed in foetal and adult islet cells. Significance Our data show a strong expression of Tβ4 in the human gut and in endocrine pancreas during development. The observed differential expression of Tβ4 suggests specific roles of the peptide in the gut of foetuses and adults. The observed heterogeneity of Tβ4 expression in the foetal life, ranging from a very rare detection in liver cells up to a diffuse reactivity in endocrine pancreas, should be taken into account when the role of Tβ4 in the development of human embryo is assessed. Future studies are needed to shed light on the link between Tβ4 and organogenesis.
Collapse
Affiliation(s)
- Sonia Nemolato
- Divisione di Anatomia Patologica, Dipartimento di Citomorfologia, University of Cagliari, Cagliari, Italy
| | - Tiziana Cabras
- Dipartimento di Scienze Applicate ai Biosistemi, Università di Cagliari, Cagliari, Italy
| | - Flaviana Cau
- Divisione di Anatomia Patologica, Dipartimento di Citomorfologia, University of Cagliari, Cagliari, Italy
| | - Mattia Umberto Fanari
- Divisione di Anatomia Patologica, Dipartimento di Citomorfologia, University of Cagliari, Cagliari, Italy
| | - Daniela Fanni
- Divisione di Anatomia Patologica, Dipartimento di Citomorfologia, University of Cagliari, Cagliari, Italy
| | - Barbara Manconi
- Dipartimento di Scienze Applicate ai Biosistemi, Università di Cagliari, Cagliari, Italy
| | - Irene Messana
- Dipartimento di Scienze Applicate ai Biosistemi, Università di Cagliari, Cagliari, Italy
| | - Massimo Castagnola
- Istituto di Biochimica e di Biochimica Clinica, Università Cattolica and/or Istituto per la Chimica del Riconoscimento Molecolare, CNR, Istituto Scientifico, Internazionale (ISI) Paolo VI, Roma, Italy
| | - Gavino Faa
- Divisione di Anatomia Patologica, Dipartimento di Citomorfologia, University of Cagliari, Cagliari, Italy
- * E-mail:
| |
Collapse
|
115
|
Abraira VE, Satoh T, Fekete DM, Goodrich LV. Vertebrate Lrig3-ErbB interactions occur in vitro but are unlikely to play a role in Lrig3-dependent inner ear morphogenesis. PLoS One 2010; 5:e8981. [PMID: 20126551 PMCID: PMC2813878 DOI: 10.1371/journal.pone.0008981] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 01/08/2010] [Indexed: 11/19/2022] Open
Abstract
Background The Lrig genes encode a family of transmembrane proteins that have been implicated in tumorigenesis, psoriasis, neural crest development, and complex tissue morphogenesis. Whether these diverse phenotypes reflect a single underlying cellular mechanism is not known. However, Lrig proteins contain evolutionarily conserved ectodomains harboring both leucine-rich repeats and immunoglobulin domains, suggesting an ability to bind to common partners. Previous studies revealed that Lrig1 binds to and inhibits members of the ErbB family of receptor tyrosine kinases by inducing receptor internalization and degradation. In addition, other receptor tyrosine kinase binding partners have been identified for both Lrig1 and Lrig3, leaving open the question of whether defective ErbB signaling is responsible for the observed mouse phenotypes. Methodology/Principal Findings Here, we report that Lrig3, like Lrig1, is able to interact with ErbB receptors in vitro. We examined the in vivo significance of these interactions in the inner ear, where Lrig3 controls semicircular canal formation by determining the timing and extent of Netrin1 expression in the otic vesicle epithelium. We find that ErbB2 and ErbB3 are present in the early otic epithelium, and that Lrig3 acts cell-autonomously here, as would be predicted if Lrig3 regulates ErbB2/B3 activity. However, inhibition of ErbB activation in the chick otic vesicle has no detectable effect on Netrin gene expression or canal morphogenesis. Conclusions/Significance Our results suggest that although both Lrig1 and Lrig3 can interact with ErbB receptors in vitro, modulation of Neuregulin signaling is unlikely to contribute to Lrig3-dependent processes of inner ear morphogenesis. These results highlight the similar binding properties of Lrig1 and Lrig3 and underscore the need to determine how these two family members bind to and regulate different receptors to affect diverse aspects of cell behavior in vivo.
Collapse
Affiliation(s)
- Victoria E. Abraira
- Department of Neurobiology and Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Takunori Satoh
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Donna M. Fekete
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Lisa V. Goodrich
- Department of Neurobiology and Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
116
|
Abstract
Background The retinal determination (RD) network is an evolutionarily conserved regulatory circuit that governs early events in the development of eyes throughout the animal kingdom. Ectopic expression of many members of this network leads to the transformation of non-retinal epithelia into eye tissue. An often-overlooked observation is that only particular cell-populations within a handful of tissues are capable of having their primary developmental instructions superseded and overruled. Methodology/Preliminary Findings Here we confirm that indeed, only a discrete number of cell populations within the imaginal discs that give rise to the head, antenna, legs, wings and halteres have the cellular plasticity to have their developmental fates altered. In contrast to previous reports, we find that all transformable cell populations do not lie within the TGFβ or Hedgehog signaling domains. Additionally neither signaling cascade alone is sufficient for non-retinal cell types to be converted into retinal tissue. The transformation “hot spots” that we have identified appear to coincide with several previously defined transdetermination “weak spots”, suggesting that ectopic eye formation is less the result of one network overriding the orders of another, as previously thought, but rather is the physical manifestation of redirecting cell populations of enormous cellular plasticity. We also demonstrate that the initiation of eye formation in non-retinal tissues occurs asynchronously compared to that of the normal eye suggesting that retinal development is not under the control of a global developmental clock. Conclusions/Significance We conclude that the subregions of non-retinal tissues that are capable of supporting eye formation represent specialized cell-populations that have a different level of plasticity than other cells within these tissues and may be the founder cells of each tissue.
Collapse
Affiliation(s)
- Claire L. Salzer
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Justin P. Kumar
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
- * E-mail:
| |
Collapse
|
117
|
Joshi SD, von Dassow M, Davidson LA. Experimental control of excitable embryonic tissues: three stimuli induce rapid epithelial contraction. Exp Cell Res 2010; 316:103-14. [PMID: 19686733 PMCID: PMC2789981 DOI: 10.1016/j.yexcr.2009.08.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 08/08/2009] [Accepted: 08/11/2009] [Indexed: 11/26/2022]
Abstract
Cell generated contractility is a major driver of morphogenesis during processes such as epithelial bending and epithelial-to-mesenchymal transitions. Previous studies of contraction in embryos have relied on developmentally programmed cell shape changes such as those that accompany ventral furrow formation in Drosophila, bottle cell formation in Xenopus, ingression in amniote embryos, and neurulation in vertebrate embryos. We have identified three methods to reproducibly and acutely induce contraction in embryonic epithelial sheets: laser activation, electrical stimulation, and nano-perfusion with chemicals released by wounding. Contractions induced by all three methods occur over a similar time-scale (1 to 2 min) and lead to reorganization of the F-actin cytoskeleton. By combining induced contractions with micro-aspiration we can simultaneously measure the stiffness of the tissue and the force and work done by contractions. Laser activation allows real-time visualization of F-actin remodeling during contraction. Perfusion with cell lysate suggests that these three stimuli activate physiologically relevant pathways that maintain epithelial tension or trigger epithelial morphogenesis. Our methods provide the means to control and study cellular contractility and will allow dissection of molecular mechanisms and biomechanics of cellular contractility.
Collapse
Affiliation(s)
| | | | - Lance. A. Davidson
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave., Pittsburgh PA, 15260
| |
Collapse
|
118
|
Pierreux C. [Personal contribution to the study of the formation of the tubular epithelial structures]. Bull Mem Acad R Med Belg 2010; 165:278-284. [PMID: 21513114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The function of glandular organs (mammary and salivary glands, exocrine pancreas) depends on their branched tubular epithelial architecture. During pancreas and salivary glands development, we have shown the succession of two opposite epithelial transitions (monolayer --> mass --> tubulo-glandular monolayers). These transitions are controlled by paracrine interactions via mesenchymal cells (SDF-1) and endothelial cells (VEGF), and coordinated by transcriptional networks. The transcription factor HNF-6 is indispensable for tube formation; ZONAB is an actor of the proliferation/differentiation switch, highly expressed in the proliferating epithelial mass. Understanding the mechanisms that control branched glandular differentiation is important for developmental biology and could shed light on polykystic diseases and in situ carcinomas.
Collapse
|
119
|
Abstract
Cell adhesion to the extracellular matrix (ECM) is mediated by the integrin family of transmembrane receptors. Integrins link ECM ligands to the cytoskeleton, providing strong attachment to enable cell-shape change and tissue integrity. This connection is made possible by an intracellular complex of proteins, which links to actin filaments and controls signalling cascades that regulate cytoskeletal rearrangements. We have identified stress-fibre-associated focal adhesions that change their composition during tissue morphogenesis. Early expression of alphaPS1betaPS integrin decreases the levels of the actin-nucleating factors Enabled, Diaphanous and profilin, as well as downregulating the amount of F-actin incorporated into the stress fibres. As follicle cells mature in their developmental pathway and become squamous, the integrin in the focal adhesions changes from alphaPS1betaPS to alphaPS2betaPS. During the switch, stress fibres increase their length and change orientation, first changing by 90 degrees and then reorienting back. The normal rapid reorientation requires new expression of alphaPS2betaPS, which also permits recruitment of the adaptor protein tensin. Unexpectedly, it is the extracellular portion of the alphaPS2 subunit that provides the specificity for intracellular recruitment of tensin. Molecular variation of the integrin complex is thus a key component of developmentally programmed morphogenesis.
Collapse
Affiliation(s)
- Isabelle Delon
- Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | | |
Collapse
|
120
|
Thiery JP. [Epithelial-mesenchymal transitions in cancer onset and progression]. Bull Acad Natl Med 2009; 193:1969-1979. [PMID: 20666011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Epithelial-mesenchymal transition (EMT) is a major process controlling multiple developmental events. The mesenchyme appeared as a transient state in diploblasts more than 800 million years ago. EMT has been conserved through evolution to control morphogenetic events, such as the formation of the three primary germ layers during gastrulation. Interestingly, related signal transduction pathways are remarkably conserved in many species. In the animal kingdom, EMT controls the intercellular adhesion machinery and its associated cytoskeleton. EMT pathways are also intimately involved in determination and differentiation programs, and are reactivated in adult tissues following injury or exposure to toxic agents. EMT is likely to play a role in early steps of carcinoma invasion, enabling blood or lymph vessel intravasation. Mesenchymal-like carcinoma cells undergo a mesenchymal to epithelial transition at distant sites from the primary tumor, and eventually form macrometastases. The mesenchymal-like state of cancer cells confers stemness, protection from cell death, immune escape and, most importantly, resistance to conventional and targeted therapies. Current strategies based on the EMT concept are aimed at designing new therapeutic approaches that interfere with the plasticity of carcinoma cells.
Collapse
Affiliation(s)
- Jean-Paul Thiery
- Institute of Molecular Cell Biology, Experimental Therapeutic Center, 61 Biopolis Drive and Cancer Science Institute, 28 Medical Drive 117456, National University of Singapore, Republic of Singapore.
| |
Collapse
|
121
|
Aguilar JL, Kulkarni R, Randis TM, Soman S, Kikuchi A, Yin Y, Ratner AJ. Phosphatase-dependent regulation of epithelial mitogen-activated protein kinase responses to toxin-induced membrane pores. PLoS One 2009; 4:e8076. [PMID: 19956644 PMCID: PMC2778951 DOI: 10.1371/journal.pone.0008076] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 11/06/2009] [Indexed: 11/29/2022] Open
Abstract
Diverse bacterial species produce pore-forming toxins (PFT) that can puncture eukaryotic cell membranes. Host cells respond to sublytic concentrations of PFT through conserved intracellular signaling pathways, including activation of mitogen-activated protein kinases (MAPK), which are critical to cell survival. Here we demonstrate that in respiratory epithelial cells p38 and JNK MAPK were phosphorylated within 30 min of exposure to pneumolysin, the PFT from Streptococcus pneumoniae. This activation was tightly regulated, and dephosphorylation of both MAPK occurred within 60 min following exposure. Pretreatment of epithelial cells with inhibitors of cellular phosphatases, including sodium orthovanadate, calyculin A, and okadaic acid, prolonged and intensified MAPK activation. Specific inhibition of MAPK phosphatase-1 did not affect the kinetics of MAPK activation in PFT-exposed epithelial cells, but siRNA-mediated knockdown of serine/threonine phosphatases PP1 and PP2A were potent inhibitors of MAPK dephosphorylation. These results indicate an important role for PP1 and PP2A in termination of epithelial responses to PFT and only a minor contribution of dual-specificity phosphatases, such as MAPK phosphatase-1, which are the major regulators of MAPK signals in other cell types. Epithelial regulation of MAPK signaling in response to membrane disruption involves distinct pathways and may require different strategies for therapeutic interventions.
Collapse
Affiliation(s)
- Jorge L. Aguilar
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Ritwij Kulkarni
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Tara M. Randis
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Sandeep Soman
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Alexander Kikuchi
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Yuxin Yin
- Department of Radiation Oncology, Columbia University, New York, New York, United States of America
| | - Adam J. Ratner
- Department of Pediatrics, Columbia University, New York, New York, United States of America
- Department of Microbiology & Immunology, Columbia University, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
122
|
Chi X, Michos O, Shakya R, Riccio P, Enomoto H, Licht JD, Asai N, Takahashi M, Ohgami N, Kato M, Mendelsohn C, Costantini F. Ret-dependent cell rearrangements in the Wolffian duct epithelium initiate ureteric bud morphogenesis. Dev Cell 2009; 17:199-209. [PMID: 19686681 DOI: 10.1016/j.devcel.2009.07.013] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 07/08/2009] [Accepted: 07/16/2009] [Indexed: 11/15/2022]
Abstract
While the genetic control of renal branching morphogenesis has been extensively described, the cellular basis of this process remains obscure. GDNF/RET signaling is required for ureter and kidney development, and cells lacking Ret are excluded from the tips of the branching ureteric bud in chimeric kidneys. Here, we find that this exclusion results from earlier Ret-dependent cell rearrangements in the caudal Wolffian duct, which generate a specialized epithelial domain that later emerges as the tip of the primary ureteric bud. By juxtaposing cells with elevated or reduced RET activity, we find that Wolffian duct cells compete, based on RET signaling levels, to contribute to this domain. At the same time, the caudal Wolffian duct transiently converts from a simple to a pseudostratified epithelium, a process that does not require Ret. Thus, both Ret-dependent cell movements and Ret-independent changes in the Wolffian duct epithelium contribute to ureteric bud formation.
Collapse
Affiliation(s)
- Xuan Chi
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
123
|
Varnat F, Zacchetti G, Ruiz i Altaba A. Hedgehog pathway activity is required for the lethality and intestinal phenotypes of mice with hyperactive Wnt signaling. Mech Dev 2009; 127:73-81. [PMID: 19861162 DOI: 10.1016/j.mod.2009.10.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 10/12/2009] [Accepted: 10/16/2009] [Indexed: 01/07/2023]
Abstract
Several lines of evidence point to the central role of WNT signaling in the initiation of intestinal tumorigenesis, most often due to loss of APC, a negative regulator of the WNT-betaCATENIN/TCF pathway. Modeling human colon cancers in mice through loss of Apc has shown that inappropriate activation of Wnt signaling is sufficient to induce adenoma formation. More recent analyses have also demonstrated a key role for HEDGEHOG-GLI (HH-GLI) signaling in human colon cancers. However, how the WNT and HH pathways interact during intestinal development, homeostasis and cancer is not clear. Marker analyses suggest predominant paracrine signaling from rare Shh producing cells in the crypt's bottom to adjacent Gli1(+) mesenchymal cells in normal adult mice. Using conditional KO models, we show that inhibition of the function of the critical Hh mediator Smoothened (Smo) rescues the lethality and intestinal phenotypes of loss of Apc. The results uncover an essential role of the Hh pathway in tumors induced by hyperactive Wnt signaling, suggest the action of the Hh pathway in parallel or downstream of Wnt signaling, and validate this model for its use in preclinical work testing Hh pathway antagonists.
Collapse
Affiliation(s)
- Frédéric Varnat
- University of Geneva Medical School, Department Genetic Medicine and Development, Geneva, Switzerland
| | | | | |
Collapse
|
124
|
Griend DJV, Konishi Y, De Marzo AM, Isaacs JT, Meeker AK. Dual-label centromere and telomere FISH identifies human, rat, and mouse cell contribution to Multispecies recombinant urogenital sinus xenografts. Prostate 2009; 69:1557-64. [PMID: 19562732 PMCID: PMC4086486 DOI: 10.1002/pros.21001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Recombinant xenografts of human cells growing in immunocompromised rodents are widely used for studying stem cell biology, tumor biology, and epithelial to mesenchyme transitions. Of critical importance is the correct interpretation of the cellular composition of such xenografts. METHODS Here we present a rapid and robust method employing protein nucleic acid (PNA) FISH probes to dual-label centromeres and telomeres (Cen/Tel FISH). Such labeling allows unambiguous discrimination between human, mouse, and rat cells in paraffin-embedded tissue sections, providing significant advantages over current methods used to discern human versus rodent cell types. RESULTS Using an in vivo prostatic developmental system where rat embryonic urogenital sinus mesenchyme is recombined with human prostate epithelial organoids and grown in an immunocompromised mouse, Cen/Tel FISH documents that all three species contribute to the development of glandular structures. CONCLUSIONS The method is an indispensable tool to analyze xenograft/host interactions and prevent misinterpretation of data using tissue recombination approaches.
Collapse
Affiliation(s)
- Donald J. Vander Griend
- Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
- The Brady Urological Institute,The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Yuko Konishi
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Angelo M. De Marzo
- The Brady Urological Institute,The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - John T. Isaacs
- Chemical Therapeutics Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
- The Brady Urological Institute,The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alan K. Meeker
- The Brady Urological Institute,The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Correspondence to: Alan K. Meeker, PhD, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, 1650 Orleans St., Baltimore, MD 21231.
| |
Collapse
|
125
|
Ciarletta P, Ben Amar M, Labouesse M. Continuum model of epithelial morphogenesis during Caenorhabditis elegans embryonic elongation. Philos Trans A Math Phys Eng Sci 2009; 367:3379-3400. [PMID: 19657005 DOI: 10.1098/rsta.2009.0088] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The purpose of this work is to provide a biomechanical model to investigate the interplay between cellular structures and the mechanical force distribution during the elongation process of Caenorhabditis elegans embryos. Epithelial morphogenesis drives the elongation process of an ovoid embryo to become a worm-shaped embryo about four times longer and three times thinner. The overall anatomy of the embryo is modelled in the continuum mechanics framework from the structural organization of the subcellular filaments within epithelial cells. The constitutive relationships consider embryonic cells as homogeneous materials with an active behaviour, determined by the non-muscle myosin II molecular motor, and a passive viscoelastic response, related to the directional properties of the filament network inside cells. The axisymmetric elastic solution at equilibrium is derived by means of the incompressibility conditions, the continuity conditions for the overall embryo deformation and the balance principles for the embryonic cells. A particular analytical solution is proposed from a simplified geometry, demonstrating the mechanical role of the microtubule network within epithelial cells in redistributing the stress from a differential contraction of circumferentially oriented actin filaments. The theoretical predictions of the biomechanical model are discussed within the biological scenario proposed through genetic analysis and pharmacological experiments.
Collapse
Affiliation(s)
- P Ciarletta
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
| | | | | |
Collapse
|
126
|
Yang TL, Young TH. Chitosan cooperates with mesenchyme-derived factors in regulating salivary gland epithelial morphogenesis. J Cell Mol Med 2009; 13:2853-63. [PMID: 18627424 PMCID: PMC4498941 DOI: 10.1111/j.1582-4934.2008.00425.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 05/24/2008] [Indexed: 12/15/2022] Open
Abstract
Chitosan is a widely used biocompatible biomaterial in the tissue regeneration, but its utility and application in the tissue morphogenesis of salivary gland remains unclear. The study aimed to explore the effects of chitosan on the epithelial morphogenesis of submandibular gland (SMG). With chitosan, the branching morphogenesis of the whole SMG explant was facilitated, and the morphogenetic-promoting effects of mesenchymal tissue on SMG were further enhanced. Furthermore, chitosan was competent to induce recombined SMG epithelium to form branches in the serum-free condition independently. In the presence of chitosan, the morphogenetic efficacy of mesenchyme-derived growth factors responsible for epithelial morphogenesis including fibroblast growth factors 7, fibroblast growth factor 10 and hepatocyte growth factor increased. The specific epithelial phenotype induced by individual growth factor, which was required for the accomplishment of salivary epithelial morphogenesis, was promoted by chitosan. Moreover, the proliferative and the chemotactic properties of these growth factors towards the SMG epithelia were also reinforced by chitosan. Therefore, in orchestrating and intensifying the essential mesenchyme-derived growth factors, chitosan is versatile in mediating SMG epithelium to form a predetermined phenotype more efficiently and comprehensively. This study suggested that chitosan is a morphogenetic-regulating biomaterial for salivary tissue, which might be useful for the future salivary gland investigation and regeneration.
Collapse
Affiliation(s)
- Tsung-Lin Yang
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan UniversityTaipei, Taiwan
- Department of Otolaryngology, National Taiwan University Hospital and College of MedicineTaipei, Taiwan
- Department of Otolaryngology, Yun-Lin Branch of National Taiwan University HospitalDouliu,Yunlin, Taiwan
| | - Tai-Horng Young
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan UniversityTaipei, Taiwan
| |
Collapse
|
127
|
Woolworth JA, Nallamothu G, Hsu T. The Drosophila metastasis suppressor gene Nm23 homolog, awd, regulates epithelial integrity during oogenesis. Mol Cell Biol 2009; 29:4679-90. [PMID: 19581292 PMCID: PMC2725718 DOI: 10.1128/mcb.00297-09] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 04/07/2009] [Accepted: 06/24/2009] [Indexed: 11/20/2022] Open
Abstract
The expression levels of the metastasis suppressor gene Nm23 have been shown to correlate positively or inversely with prognosis in different cancer cohorts. This indicates that Nm23 may be needed at different expression levels and may function differently in various tissues. Here we report a novel epithelial function of the Drosophila melanogaster homolog of human Nm23, abnormal wing discs (awd). We show a dynamic expression pattern of the Awd protein during morphogenesis of the Drosophila follicle cells during oogenesis. Loss-of-function awd mutant cells result in the accumulation and spreading of adherens junction components, such as Drosophila E-cadherin, beta-catenin/Armadillo, and alpha-spectrin, and the disruption of epithelial integrity, including breaking up of the epithelial sheet and piling up of follicle cells. In contrast, overexpression of awd diminishes adherens junction components and induces a mesenchymal-cell-like cell shape change. The gain-of-function phenotype is consistent with a potential oncogenic function of this metastasis suppressor gene. Interestingly, we demonstrate that the epithelial function of awd is mediated by Rab5 and show that the Rab5 expression level is downregulated in awd mutant cells. Therefore, awd modulates the level and localization of adherens junction components via endocytosis. This is the first demonstration of an in vivo function of Nm23 family genes in regulating epithelial morphogenesis.
Collapse
Affiliation(s)
- Julie A Woolworth
- Department of Pathology and Laboratory Medicine and Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425, USA
| | | | | |
Collapse
|
128
|
Hage E. Electron microscopic identification of endocrine cells in the bronchial epithelium of human foetuses. Acta Pathol Microbiol Scand A 2009; 80:143-4. [PMID: 4634708 DOI: 10.1111/j.1699-0463.1972.tb00281.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
129
|
Slanchev K, Carney TJ, Stemmler MP, Koschorz B, Amsterdam A, Schwarz H, Hammerschmidt M. The epithelial cell adhesion molecule EpCAM is required for epithelial morphogenesis and integrity during zebrafish epiboly and skin development. PLoS Genet 2009; 5:e1000563. [PMID: 19609345 PMCID: PMC2700972 DOI: 10.1371/journal.pgen.1000563] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 06/16/2009] [Indexed: 12/13/2022] Open
Abstract
The aberrant expression of the transmembrane protein EpCAM is associated with tumor progression, affecting different cellular processes such as cell–cell adhesion, migration, proliferation, differentiation, signaling, and invasion. However, the in vivo function of EpCAM still remains elusive due to the lack of genetic loss-of-function studies. Here, we describe epcam (tacstd) null mutants in zebrafish. Maternal-zygotic mutants display compromised basal protrusive activity and epithelial morphogenesis in cells of the enveloping layer (EVL) during epiboly. In partial redundancy with E-cadherin (Ecad), EpCAM made by EVL cells is further required for cell–cell adhesion within the EVL and, possibly, for proper attachment of underlying deep cells to the inner surface of the EVL, thereby also affecting deep cell epiboly movements. During later development, EpCAM per se becomes indispensable for epithelial integrity within the periderm of the skin, secondarily leading to disrupted morphology of the underlying basal epidermis and moderate hyper-proliferation of skin cells. On the molecular level, EVL cells of epcam mutant embryos display reduced levels of membranous Ecad, accompanied by an enrichment of tight junction proteins and a basal extension of apical junction complexes (AJCs). Our data suggest that EpCAM acts as a partner of E-cadherin to control adhesiveness and integrity as well as plasticity and morphogenesis within simple epithelia. In addition, EpCAM is required for the interaction of the epithelia with underlying cell layers. EpCAM is a well-established marker for carcinomas of epithelial origin and a potential target for immunotherapy. In vitro analyses have implicated EpCAM in a plethora of different cellular processes, such as adhesion, motility, proliferation, differentiation, and signaling. Strikingly, depending on the context, EpCAM displayed rather opposite effects, either promoting or attenuating cell–cell adhesion versus cell migration and tissue invasion, a phenomenon described as the “double-face” of EpCAM. However, the in vivo relevance of its different effects remained largely unclear. Here, we present the first genetic analysis of EpCAM function in vivo, based on loss-of-function mutants in the zebrafish. As it is in mammals, zebrafish EpCAM is expressed in simple epithelia. Mutant embryos display defects both in epithelial morphogenesis and in epithelial integrity. Reduced epithelial morphogenesis is accompanied, and possibly caused, by an extension of apical junctional complexes and compromised basal protrusive activity. Furthermore, mutant epithelia display alterations in the relative abundance of adherence junction versus tight junction components. In addition, EpCAM tightly cooperates with E-cadherin and has a previously unrecognized trans effect on the morphogenesis and integrity of underlying cell layers. Cell differentiation and proliferation in EpCAM mutants are not, or only secondarily, affected. During later development and adulthood, EpCAM is largely dispensable, reinforcing its suitability as a target for anti-carcinoma immunotherapy with minimal side effects.
Collapse
Affiliation(s)
- Krasimir Slanchev
- Georges-Koehler-Laboratory, Max-Planck Institute of Immunobiology, Freiburg, Germany
| | - Thomas J. Carney
- Georges-Koehler-Laboratory, Max-Planck Institute of Immunobiology, Freiburg, Germany
| | - Marc P. Stemmler
- Department of Molecular Embryology, Max-Planck Institute of Immunobiology, Freiburg, Germany
| | - Birgit Koschorz
- Georges-Koehler-Laboratory, Max-Planck Institute of Immunobiology, Freiburg, Germany
| | - Adam Amsterdam
- Koch Institute for Integrative Cancer Research, Cambridge, Massachusetts, United States of America
| | - Heinz Schwarz
- Max-Planck Institute of Developmental Biology, Tübingen, Germany
| | - Matthias Hammerschmidt
- Georges-Koehler-Laboratory, Max-Planck Institute of Immunobiology, Freiburg, Germany
- Institute for Developmental Biology, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail:
| |
Collapse
|
130
|
Bauer R, Weimbs A, Lechner H, Hoch M. DE-Cadherin, a Core Component of the Adherens Junction Complex Modifies Subcellular Localization of theDrosophilaGap Junction Protein Innexin2. ACTA ACUST UNITED AC 2009; 13:103-14. [PMID: 16613784 DOI: 10.1080/15419060600631839] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The Drosophila innexin multigene family of gap junction encoding proteins consists of eight family members whose function in epithelial morphogenesis is mostly unknown. We have recently shown that innexin2 plays a crucial role in the organization of embryonic epithelia. Innexin2 protein accumulates in the epidermis in the apico-lateral membrane domain and colocalizes with core proteins of adherens junctions, such as DE-cadherin and Armadillo, the ss -catenin homolog. Innexin2 localization is altered in both armadillo and DE-cadherin mutants Biochemical interaction studies point to a direct interaction of DE-cadherin and Armadillo with innexin2 suggesting a close link between gap junction and adherens junction biogenesis. We have used the Drosophila Schneider cell tissue culture system to further study the interaction of innexin2 with DE-cadherin. Our results provide evidence that DE-cadherin may be a key component to control trafficking, and localization of Innexin2 to the plasma membrane.
Collapse
Affiliation(s)
- R Bauer
- Institute of Molecular Physiology and Developmental Biology, University of Bonn, Bonn, Germany
| | | | | | | |
Collapse
|
131
|
Snider P, Tang S, Lin G, Wang J, Conway SJ. Generation of Smad7(-Cre) recombinase mice: A useful tool for the study of epithelial-mesenchymal transformation within the embryonic heart. Genesis 2009; 47:469-75. [PMID: 19415626 PMCID: PMC2761032 DOI: 10.1002/dvg.20524] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Smad7 can be induced by various transforming growth factor-beta superfamily ligands and negatively modulates their signaling, thus acting in a negative, autocrine feedback manner. Previous analyses have demonstrated that although Smad7 is widely expressed, it is predominantly found in the vascular endothelium. Because of the restricted spatiotemporal reporter expression driven via a novel 4.3 kb Smad7 promoter in endocardial cells overlying the hearts atrioventricular (AV) cushions; we hypothesized that a transgenic Cre line would prove useful for the analysis of endocardial cushion and valve formation. Here we describe a mouse line, Smad7(Cre), where Cre is robustly expressed within both cardiac outflow and AV endocardial cushions. Additionally, as endocardial cells are thought to contribute at least in part to the formation of the endocardial cushion mesenchyme, we crossed the Smad7(Cre) mice to the ROSA26(eGFP-DTA) diphtheria toxin A-expressing mice in order to genetically ablate Smad7(Cre) expressing cells. Ablation of Smad7(Cre) cells resulted in embryonic lethality by E11.5 and largely acellular endocardial cushions.
Collapse
Affiliation(s)
- Paige Snider
- Riley Heart Research Center, HB Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Sunyong Tang
- Riley Heart Research Center, HB Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Goldie Lin
- Riley Heart Research Center, HB Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jian Wang
- Riley Heart Research Center, HB Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Simon J. Conway
- Riley Heart Research Center, HB Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
| |
Collapse
|
132
|
Ghosh B, Benyumov AO, Ghosh P, Jia Y, Avdulov S, Dahlberg PS, Peterson M, Smith K, Polunovsky VA, Bitterman PB, Wagner CR. Nontoxic chemical interdiction of the epithelial-to-mesenchymal transition by targeting cap-dependent translation. ACS Chem Biol 2009; 4:367-77. [PMID: 19351181 PMCID: PMC2796976 DOI: 10.1021/cb9000475] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Normal growth and development depends upon high fidelity regulation of cap-dependent translation initiation, a process that is usurped and redirected in cancer to mediate acquisition of malignant properties. The epithelial-to-mesenchymal transition (EMT) is a key translationally regulated step in the development of epithelial cancers and pathological tissue fibrosis. To date, no compounds targeting EMT have been developed. Here we report the synthesis of a novel class of histidine triad nucleotide binding protein (HINT)-dependent pronucleotides that interdict EMT by negatively regulating the association of eIF4E with the mRNA cap. Compound eIF4E inhibitor-1 potently inhibited cap-dependent translation in a dose-dependent manner in zebrafish embryos without causing developmental abnormalities and prevented eIF4E from triggering EMT in zebrafish ectoderm explants without toxicity. Metabolism studies with whole cell lysates demonstrated that the prodrug was rapidly converted into 7-BnGMP. Thus we have successfully developed the first nontoxic small molecule able to inhibit EMT, a key process in the development of epithelial cancer and tissue fibrosis, by targeting the interaction of eIF4E with the mRNA cap and demonstrated the tractability of zebrafish as a model organism for studying agents that modulate EMT. Our work provides strong motivation for the continued development of compounds designed to normalize cap-dependent translation as novel chemo-preventive agents and therapeutics for cancer and fibrosis.
Collapse
Affiliation(s)
- Brahma Ghosh
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alexey O. Benyumov
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Phalguni Ghosh
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yan Jia
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Svetlana Avdulov
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Peter S. Dahlberg
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mark Peterson
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Karen Smith
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Peter B. Bitterman
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Carston R. Wagner
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| |
Collapse
|
133
|
Soukup GA, Fritzsch B, Pierce ML, Weston MD, Jahan I, McManus MT, Harfe BD. Residual microRNA expression dictates the extent of inner ear development in conditional Dicer knockout mice. Dev Biol 2009; 328:328-41. [PMID: 19389351 PMCID: PMC2793102 DOI: 10.1016/j.ydbio.2009.01.037] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 01/25/2009] [Accepted: 01/27/2009] [Indexed: 01/09/2023]
Abstract
Inner ear development requires coordinated transformation of a uniform sheet of cells into a labyrinth with multiple cell types. While numerous regulatory proteins have been shown to play critical roles in this process, the regulatory functions of microRNAs (miRNAs) have not been explored. To demonstrate the importance of miRNAs in inner ear development, we generated conditional Dicer knockout mice by the expression of Cre recombinase in the otic placode at E8.5. Otocyst-derived ganglia exhibit rapid neuron-specific miR-124 depletion by E11.5, degeneration by E12.5, and profound defects in subsequent sensory epithelial innervations by E17.5. However, the small and malformed inner ear at E17.5 exhibits residual and graded hair cell-specific miR-183 expression in the three remaining sensory epithelia (posterior crista, utricle, and cochlea) that closely corresponds to the degree of hair cell and sensory epithelium differentiation, and Fgf10 expression required for morphohistogenesis. The highest miR-183 expression is observed in near-normal hair cells of the posterior crista, whereas the reduced utricular macula demonstrates weak miR-183 expression and develops presumptive hair cells with numerous disorganized microvilli instead of ordered stereocilia. The correlation of differential and delayed depletion of mature miRNAs with the derailment of inner ear development demonstrates that miRNAs are crucial for inner ear neurosensory development and neurosensory-dependent morphogenesis.
Collapse
Affiliation(s)
- Garrett A Soukup
- Department of Biomedical Sciences, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.
| | | | | | | | | | | | | |
Collapse
|
134
|
Xiong W, He F, Morikawa Y, Yu X, Zhang Z, Lan Y, Jiang R, Cserjesi P, Chen Y. Hand2 is required in the epithelium for palatogenesis in mice. Dev Biol 2009; 330:131-41. [PMID: 19341725 DOI: 10.1016/j.ydbio.2009.03.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 03/20/2009] [Accepted: 03/21/2009] [Indexed: 01/03/2023]
Abstract
The basic helix-loop-helix (bHLH) transcription factor Hand2 has been implicated in the development of multiple organs, including craniofacial organs. Mice carrying Hand2 hypomorphic alleles (Hand2(LoxP/-)) display a cleft palate phenotype. A specific deletion of the Hand2 branchial arch-specific enhancer also leads to a hypoplastic mandible and cleft palate formation in mice. However, the underlying mechanism of Hand2 regulation of palate development remains unknown. Here we show that Hand2 is expressed in both the epithelium and mesenchyme of the developing palate. While mesenchymal specific inactivation of Hand2 has no impact on palate development, epithelial specific deletion of Hand2 creates a cleft palate phenotype. Hand2 appears to exert distinct roles in the anterior and posterior palate. In the anterior palate of Hand2(LoxP/-) mice, premature death of periderm cells and a down-regulation of Shh are observed in the medial edge epithelium (MEE), accompanied by a decreased level of cell proliferation in the palatal mesenchyme. In the posterior palate, a lower dose of Hand2 causes aberrant periderm cell death on the surface of the epithelium, triggering abnormal fusion between the palatal shelf and mandible and preventing palatal shelf elevation. We further demonstrate that BMP activities are essential for the expression of Hand2 in the palate. We conclude that Hand2 is an intrinsic regulator in the epithelium and is required for palate development.
Collapse
Affiliation(s)
- Wei Xiong
- Division of Developmental Biology, Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
135
|
Abstract
Interactions between adjacent epithelial and mesenchymal tissues represent a highly conserved mechanism in embryonic organogenesis. In particular, the ability of the mesenchyme to instruct cellular differentiation of the epithelium is a fundamental requirement for the morphogenesis of tubular structures such as those found in the kidneys, lungs, and the developing male reproductive system. Once the tubular structure has formed, it receives signals from the mesenchyme, which can control proliferation, patterning, and differentiation of the epithelium inside the tube. However, the epithelium is not a "silent partner" in this process, and epithelium-derived factors are often required for proper maintenance of the mesenchymal compartment. Although much emphasis has been placed on the characterization of mesenchymally-derived signals required for epithelial differentiation, it is important to note that epithelial-mesenchymal interactions are a two-way street wherein each compartment requires the presence of the other for proper tubule morphogenesis and function. In this review, we discuss epithelial-mesenchymal interactions in the processes of Wolffian duct and fetal testis cord development using the mouse as a model organism and propose inhibin beta A as a conserved mesenchyme-derived regulator in these two male-specific tubular structures.
Collapse
Affiliation(s)
- Denise R. Archambeault
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
| | - Jessica Tomaszewski
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
| | - Avenel Joseph
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
| | - Barry T. Hinton
- Department of Cell Biology, School of Medicine, University of Virginia, Charlottesville, Virginia
| | - Humphrey Hung-Chang Yao
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
| |
Collapse
|
136
|
Bykov VL. [Juxtaoral organ of Chievitz]. Morfologiia 2009; 136:85-94. [PMID: 20358781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This review presents the analysis of the systematized data on human juxtaoral organ (JOO) development, structure and function based on the results of classical and recent morphological studies. JOO morphogenesis is traced, including the appearance of its anlage at the bottom of the primitive mouth, epithelial invagination into the mesenchyme, JOO detachment from the oral epithelium, its innervation, connective tissue capsule formation, and final maturation. The analysis of the results of macroscopical, histological, electron microscopical, histochemical and immunohistochemical studies is presented, suggesting high metabolic and synthetic activity of its epithelium, which expresses several neural markers, and emphasizing a rich innervation of both its epithelial and stromal components. The findings supporting the concepts of JOO secretory and mechanosensory functions, are examined. The data on the differential diagnosis between JOO and tumoral processes are discussed, as well as the pathological changes of JOO itself and their significance for the diagnosis of the diseases.
Collapse
|
137
|
Cervantes S, Yamaguchi TP, Hebrok M. Wnt5a is essential for intestinal elongation in mice. Dev Biol 2008; 326:285-94. [PMID: 19100728 DOI: 10.1016/j.ydbio.2008.11.020] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 11/15/2008] [Accepted: 11/25/2008] [Indexed: 11/20/2022]
Abstract
Morphogenesis of the mammalian small intestine entails extensive elongation and folding of the primitive gut into a tightly coiled digestive tube. Surprisingly, little is known about the cellular and molecular mechanisms that mediate the morphological aspects of small intestine formation. Here, we demonstrate that Wnt5a, a member of the Wnt family of secreted proteins, is essential for the development and elongation of the small intestine from the midgut region. We found that the small intestine in mice lacking Wnt5a was dramatically shortened and duplicated, forming a bifurcated lumen instead of a single tube. In addition, cell proliferation was reduced and re-intercalation of post-mitotic cells into the elongating gut tube epithelium was disrupted. Thus, our study demonstrates that Wnt5a functions as a critical regulator of midgut formation and morphogenesis in mammals.
Collapse
Affiliation(s)
- Sara Cervantes
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA 94143, USA
| | | | | |
Collapse
|
138
|
Jurić-Lekić G, Radujković V, Kancijan V, Bulić-Jakus F, Lokosek V, Katusić A, Vlahović M, Serman L. Differentiation of epiglottal epithelia during prenatal and postnatal human development. Coll Antropol 2008; 32:1115-1120. [PMID: 19149217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Differentiation of epiglottal epithelia during human development was for the first time investigated by the light microscopy and documented in celoidine collection of human embryos from the Archive of the Department of Histology and Embryology, School of Medicine University of Zagreb, Croatia. At 6 weeks epiglottal swelling was found to be covered by a simple squamous epithelium consisting of a single layer of cells. At 8 weeks epithelium changed to a two-layered cuboidal epithelium which at the end of the 8th week transformed to multilayered columnar epithelium without cilia and goblet cells. In the one-day-old newborn, the majority of epiglottis was found to be covered by the mature ciliated columnar pseudostratified epithelium with goblet cells while only a minor part of the oral surface next to the tongue by the stratified squamous epithelium. This unexpected finding is in contrast to the domination of the stratified squamous epithelium found at the age of 13 years and in 35-years-old adult. Reversal of proportion covered by different types of epithelia between birth and puberty /adulthood is probably connected to the establishment of the air-flow which could be stimulating for differentiation of stratified squamous epithelium.
Collapse
Affiliation(s)
- Gordana Jurić-Lekić
- Department of Histology and Embryology, School of Medicine, University of Zagreb, Zagreb, Croatia.
| | | | | | | | | | | | | | | |
Collapse
|
139
|
Zhong LP, Yang X, Zhang L, Wei KJ, Pan HY, Zhou XJ, Li J, Chen WT, Zhang ZY. Overexpression of insulin-like growth factor binding protein 3 in oral squamous cell carcinoma. Oncol Rep 2008; 20:1441-1447. [PMID: 19020726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Previously, we established an in vitro cellular carcinogenesis model of oral squamous cell carcinoma (OSCC), including a human immortalized oral epithelial cell (HIOEC) line and its derived cancerous HB96 cell line. Further cDNA microarray analysis showed a significant up-regulated gene, insulin-like growth factor binding protein 3 (IGFBP3), accompanying with in vitro cancerization from HIOEC to HB96. In order to investigate IGFBP3 up-regulation and its potential usefulness as a molecular marker in OSCC, we detected the IGFBP3 expression with a panel of OSCC lines, and clinical samples of cancerous tissues and paired adjacent non-malignant epithelia from primary OSCC patients. Western blotting and real-time PCR showed increased IGFBP3 mRNA level and protein expression in OSCC cell lines compared with HIOEC in vitro; immunohistochemistry and real-time PCR also showed increased IGFBP3 mRNA level and protein expression in cancerous tissues compared with adjacent non-malignant epithelia from OSCC patients. Positive correlations were found between the IGFBP3 protein-positive grade in cancerous tissue and the tumor size as well as lymph node metastasis, a larger tumor size and positive lymph node metastasis indicating a higher level of IGFBP3 protein-positive grade. Based on these results, IGFBP3 may be used as a positive biomarker for OSCC development and progression.
Collapse
Affiliation(s)
- Lai-Ping Zhong
- Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, P.R. China
| | | | | | | | | | | | | | | | | |
Collapse
|
140
|
Suzuki Y. Expression of bHLH transcription factors and IGFs in the non-sensory patches, olfactory epithelium and vomeronasal organ. Chem Senses 2008; 30 Suppl 1:i125-6. [PMID: 15738072 DOI: 10.1093/chemse/bjh146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yuko Suzuki
- Department of Oral Anatomy, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu 061-0293, Japan.
| |
Collapse
|
141
|
Breer H, Hoppe R, Kaluza J, Levai O, Strotmann J. Olfactory subsystems in mammals: specific roles in recognizing chemical signals? Chem Senses 2008; 30 Suppl 1:i144-5. [PMID: 15738082 DOI: 10.1093/chemse/bjh155] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Heinz Breer
- Institute of Physiology, University of Hohenheim, D-70593 Stuttgart, Germany.
| | | | | | | | | |
Collapse
|
142
|
Lazarevich NL, Al'pern DV. [Hepatocyte nuclear factor 4 (HNF4) in epithelial development and carcinogenesis]. Mol Biol (Mosk) 2008; 42:786-797. [PMID: 18988528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Hepatocyte nuclear factors play the key role in the establishing and maintenance of hepatocyte differentiation. They not only control the expression of functional hepatic genes but are also involved in the regulation of proliferation, morphogenesis and detoxication in the liver. In this review we consider the main biological properties of the central regulator of hepatic differentiation HNF4alpha, patterns of its expression in embryogenesis and different adult tissues, mechanisms of regulation of its activity and transcriptional properties, and the essential target genes. Based on the studies of gene expression on the experimental models of rodent carcinogenesis and clinical samples of human liver tumors, the clear association of HNF4alpha transcriptional repression with progression and dedifferentiation of this type of tumors was shown. The possibility of the reversion of dedifferentiated hepatocarcinoma malignant phenotype by means of HNF4alpha exogenous expression confirms the important role of this factor in the coordination of proliferation, differentiation and the maintenance of epithelial morphology in several types of epithelial cells.
Collapse
|
143
|
Rodríguez-León J, Esteban CR, Martí M, Santiago-Josefat B, Dubova I, Rubiralta X, Belmonte JCI. Pitx2 regulates gonad morphogenesis. Proc Natl Acad Sci U S A 2008; 105:11242-7. [PMID: 18678914 PMCID: PMC2516275 DOI: 10.1073/pnas.0804904105] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Indexed: 12/17/2022] Open
Abstract
Organ shape and size, and, ultimately, organ function, relate in part to the cell and tissue spatial arrangement that takes place during embryonic development. Despite great advances in the genetic regulatory networks responsible for tissue and organ development, it is not yet clearly understood how specific gene functions are linked to the specific morphogenetic processes underlying the internal organ asymmetries found in vertebrate animals. During female chick embryogenesis, and in contrast to males where both testes develop symmetrically, asymmetrical gonad morphogenesis results in only one functional ovary. The disposition of paired organs along the left-right body axis has been shown to be regulated by the activity of the homeobox containing gene pitx2. We have found that pitx2 regulates cell adhesion, affinity, and cell recognition events in the developing gonad primordium epithelia. This in turn not only allows for proper somatic development of the gonad cortex but also permits the proliferation and differentiation of primordial germ cells. We illustrate how Pitx2 activity directs asymmetrical gonad morphogenesis by controlling mitotic spindle orientation of the developing gonad cortex and how, by modulating cyclinD1 expression during asymmetric ovarian development, Pitx2 appears to control gonad organ size. All together our observations indicate that the effects elicited by Pitx2 during the development of the female chick ovary are critical for cell topology, growth, fate, and ultimately organ morphogenesis and function.
Collapse
Affiliation(s)
- Joaquín Rodríguez-León
- *Center of Regenerative Medicine in Barcelona, Doctor Aiguader 88, 08003 Barcelona, Spain; and
| | - Concepción Rodríguez Esteban
- Gene Expression Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037
| | - Mercè Martí
- *Center of Regenerative Medicine in Barcelona, Doctor Aiguader 88, 08003 Barcelona, Spain; and
| | - Belén Santiago-Josefat
- *Center of Regenerative Medicine in Barcelona, Doctor Aiguader 88, 08003 Barcelona, Spain; and
| | - Ilir Dubova
- *Center of Regenerative Medicine in Barcelona, Doctor Aiguader 88, 08003 Barcelona, Spain; and
- Gene Expression Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037
| | - Xavier Rubiralta
- *Center of Regenerative Medicine in Barcelona, Doctor Aiguader 88, 08003 Barcelona, Spain; and
- Gene Expression Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037
| | - Juan Carlos Izpisúa Belmonte
- *Center of Regenerative Medicine in Barcelona, Doctor Aiguader 88, 08003 Barcelona, Spain; and
- Gene Expression Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037
| |
Collapse
|
144
|
Lopardo T, Lo Iacono N, Marinari B, Giustizieri ML, Cyr DG, Merlo G, Crosti F, Costanzo A, Guerrini L. Claudin-1 is a p63 target gene with a crucial role in epithelial development. PLoS One 2008; 3:e2715. [PMID: 18648642 PMCID: PMC2453228 DOI: 10.1371/journal.pone.0002715] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 06/19/2008] [Indexed: 12/31/2022] Open
Abstract
The epidermis of the skin is a self-renewing, stratified epithelium that functions as the interface between the human body and the outer environment, and acts as a barrier to water loss. Components of intercellular junctions, such as Claudins, are critical to maintain tissue integrity and water retention. p63 is a transcription factor essential for proliferation of stem cells and for stratification in epithelia, mutated in human hereditary syndromes characterized by ectodermal dysplasia. Both p63 and Claudin-1 null mice die within few hours from birth due to dehydration from severe skin abnormalities. These observations suggested the possibility that these two genes might be linked in one regulatory pathway with p63 possibly regulating Claudin-1 expression. Here we show that silencing of ΔNp63 in primary mouse keratinocytes results in a marked down-regulation of Claudin-1 expression (−80%). ΔNp63α binds in vivo to the Claudin-1 promoter and activates both the endogenous Claudin-1 gene and a reporter vector containing a –1.4 Kb promoter fragment of the Claudin-1 gene. Accordingly, Claudin-1 expression was absent in the skin of E15.5 p63 null mice and natural p63 mutant proteins, specifically those found in Ankyloblepharon–Ectodermal dysplasia–Clefting (AEC) patients, were indeed altered in their capacity to regulate Claudin-1 transcription. This correlates with deficient Claudin-1 expression in the epidermis of an AEC patient carrying the I537T p63 mutation. Notably, AEC patients display skin fragility similar to what observed in the epidermis of Claudin-1 and p63 null mice. These findings reinforce the hypothesis that these two genes might be linked in a common regulatory pathway and that Claudin-1 may is an important p63 target gene involved in the pathogenesis of ectodermal dysplasias.
Collapse
Affiliation(s)
- Teresa Lopardo
- Department of Biomolecular Sciences and Biotechnology, University of Milan, Milan, Italy
| | - Nadia Lo Iacono
- Department of Biomolecular Sciences and Biotechnology, University of Milan, Milan, Italy
| | - Barbara Marinari
- Department of Dermatology, University of Rome “Tor Vergata”, Rome, Italy
| | | | - Daniel G. Cyr
- INRS-Institut Armand-Frappier, Laval, Quebec, Canada
| | - Giorgio Merlo
- Dulbecco Telethon Laboratory, Molecular Biotech Center, University of Torino, Torino, Italy
| | | | - Antonio Costanzo
- Department of Dermatology, University of Rome “Tor Vergata”, Rome, Italy
| | - Luisa Guerrini
- Department of Biomolecular Sciences and Biotechnology, University of Milan, Milan, Italy
- * E-mail:
| |
Collapse
|
145
|
Wakefield L, Cornish V, Long H, Kawamura A, Zhang X, Hein DW, Sim E. Mouse arylamine N-acetyltransferase 2 (Nat2) expression during embryogenesis: a potential marker for the developing neuroendocrine system. Biomarkers 2008; 13:106-18. [PMID: 17896208 PMCID: PMC2430772 DOI: 10.1080/13547500701673529] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Arylamine N-acetyltransferase (NAT) genes in humans and in rodents encode polymorphic drug metabolizing enzymes. Human NAT1 (and the murine equivalent mouse Nat2) is found early in embryonic development and is likely to have an endogenous role. We report the detailed expression of the murine gene (Nat2) and encoded protein in mouse embryos, using a transgenic mouse model bearing a lacZ transgene inserted into the coding region of mouse Nat2. In mouse embryos, the transgene was expressed in sensory epithelia, epithelial placodes giving rise to visceral sensory neurons, the developing pituitary gland, sympathetic chain and urogenital ridge. In Nat2+/+ mice, the presence and activity of Nat2 protein was detected in these tissues and their adult counterparts. Altered expression of the human orthologue in breast tumours, in which there is endocrine signalling, suggests that human NAT1 should be considered as a potential biomarker for neuroendocrine tissues and tumours.
Collapse
Affiliation(s)
- Larissa Wakefield
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| | - Valerie Cornish
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| | - Hilary Long
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| | - Akane Kawamura
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| | - Xiaoyan Zhang
- Department of Pharmacology and Toxicology and James Graham Brown Center, University of Louisville School of Medecine, Kentucky, USA
| | - David W. Hein
- Department of Pharmacology and Toxicology and James Graham Brown Center, University of Louisville School of Medecine, Kentucky, USA
| | - Edith Sim
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| |
Collapse
|
146
|
Breau MA, Pietri T, Stemmler MP, Thiery JP, Weston JA. A nonneural epithelial domain of embryonic cranial neural folds gives rise to ectomesenchyme. Proc Natl Acad Sci U S A 2008; 105:7750-5. [PMID: 18515427 PMCID: PMC2408482 DOI: 10.1073/pnas.0711344105] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Indexed: 12/29/2022] Open
Abstract
The neural crest is generally believed to be the embryonic source of skeletogenic mesenchyme (ectomesenchyme) in the vertebrate head and other derivatives, including pigment cells and neurons and glia of the peripheral nervous system. Although classical transplantation experiments leading to this conclusion assumed that embryonic neural folds were homogeneous epithelia, we reported that embryonic cranial neural folds contain spatially and phenotypically distinct domains, including a lateral nonneural domain with cells that coexpress E-cadherin and PDGFRalpha and a thickened mediodorsal neuroepithelial domain where these proteins are reduced or absent. We now show that Wnt1-Cre is expressed in the lateral nonneural epithelium of rostral neural folds and that cells coexpressing Cre-recombinase and PDGFRalpha delaminate precociously from some of this nonneural epithelium. We also show that ectomesenchymal cells exhibit beta-galactosidase activity in embryos heterozygous for an Ecad-lacZ reporter knock- in allele. We conclude that a lateral nonneural domain of the neural fold epithelium, which we call "metablast," is a source of ectomesenchyme distinct from the neural crest. We suggest that closer analysis of the origin of ectomesenchyme might help to understand (i) the molecular-genetic regulation of development of both neural crest and ectomesenchyme lineages; (ii) the early developmental origin of skeletogenic and connective tissue mesenchyme in the vertebrate head; and (iii) the presumed origin of head and branchial arch skeletal and connective tissue structures during vertebrate evolution.
Collapse
Affiliation(s)
- Marie Anne Breau
- *Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, Institut Curie, 26 Rue d'Ulm, 75248 Paris Cedex 05, France
| | - Thomas Pietri
- *Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, Institut Curie, 26 Rue d'Ulm, 75248 Paris Cedex 05, France
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403-1254
| | - Marc P. Stemmler
- Department of Molecular Embryology, Max Planck-Institute of Immunobiology, Stuebeweg 51, D-79108 Freiburg, Germany; and
| | - Jean Paul Thiery
- *Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, Institut Curie, 26 Rue d'Ulm, 75248 Paris Cedex 05, France
| | - James A. Weston
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403-1254
| |
Collapse
|
147
|
Abstract
All the neurons and glial cells of the central nervous system are generated from the neuroepithelial cells in the walls of the embryonic neural tube, the 'embryonic neural stem cells'. The stem cells seem to be equivalent to the so-called 'radial glial cells', which for many years had been regarded as a specialized type of glial cell. These radial cells generate different classes of neurons in a position-dependent manner. They then switch to producing glial cells (oligodendrocytes and astrocytes). It is not known what drives the neuron-glial switch, although downregulation of pro-neural basic helix-loop-helix transcription factors is one important step. This drives the stem cells from a neurogenic towards a gliogenic mode. The stem cells then choose between developing as oligodendrocytes or astrocytes, of which there might be intrinsically different subclasses. This review focuses on the different extracellular signals and intracellular responses that influence glial generation and the choice between oligodendrocyte and astrocyte fates.
Collapse
|
148
|
Lee JD, Silva-Gagliardi NF, Tepass U, McGlade CJ, Anderson KV. The FERM protein Epb4.1l5 is required for organization of the neural plate and for the epithelial-mesenchymal transition at the primitive streak of the mouse embryo. Development 2008; 134:2007-16. [PMID: 17507402 DOI: 10.1242/dev.000885] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
During early mouse development, a single-layered epithelium is transformed into the three germ layers that are the basis of the embryonic body plan. Here we describe an ENU-induced mutation, limulus (lulu), which disrupts gastrulation and the organization of all three embryonic germ layers. Positional cloning and analysis of additional alleles show that lulu is a null allele of the FERM-domain gene erythrocyte protein band 4.1-like 5 (Epb4.1l5). During gastrulation, some cells in lulu mutants are trapped in the primitive streak at an intermediate stage of the epithelial-mesenchymal transition; as a result, the embryos have very little paraxial mesoderm. Epithelial layers of the later lulu embryo are also disrupted: definitive endoderm is specified but does not form a gut tube, and the neural plate is broad and forms ectopic folds rather than closing to make the neural tube. In contrast to zebrafish and Drosophila, in which orthologs of Epb4.1l5 control the apical localization and activity of Crumbs proteins, mouse Crumbs proteins are localized normally to the apical surface of the lulu mutant epiblast and neural plate. However, the defects in both the lulu primitive streak and neural plate are associated with disruption of the normal organization of the actin cytoskeleton. We propose that mouse Lulu (Epb4.1l5) helps anchor the actin-myosin contractile machinery to the membrane to allow the dynamic rearrangements of epithelia that mediate embryonic morphogenesis.
Collapse
Affiliation(s)
- Jeffrey D Lee
- Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10021, USA
| | | | | | | | | |
Collapse
|
149
|
Gates J, Mahaffey JP, Rogers SL, Emerson M, Rogers EM, Sottile SL, Van Vactor D, Gertler FB, Peifer M. Enabled plays key roles in embryonic epithelial morphogenesis in Drosophila. Development 2008; 134:2027-39. [PMID: 17507404 DOI: 10.1242/dev.02849] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Studies in cultured cells and in vitro have identified many actin regulators and begun to define their mechanisms of action. Among these are Enabled (Ena)/VASP proteins, anti-Capping proteins that influence fibroblast migration, growth cone motility, and keratinocyte cell adhesion in vitro. However, partially redundant family members in mammals and maternal Ena contribution in Drosophila previously prevented assessment of the roles of Ena/VASP proteins in embryonic morphogenesis in flies or mammals. We used several approaches to remove maternal and zygotic Ena function, allowing us to address this question. We found that inactivating Ena does not disrupt cell adhesion or epithelial organization, suggesting its role in these processes is cell type-specific. However, Ena plays an important role in many morphogenetic events, including germband retraction, segmental groove retraction and head involution, whereas it is dispensable for other morphogenetic movements. We focused on dorsal closure, analyzing mechanisms by which Ena acts. Ena modulates filopodial number and length, thus influencing the speed of epithelial zippering and the ability of cells to match with correct neighbors. We also explored filopodial regulation in cultured Drosophila cells and embryos. These data provide new insights into developmental and mechanistic roles of this important actin regulator.
Collapse
Affiliation(s)
- Julie Gates
- Lineberger Comprehensive Cancer Center and Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
150
|
Abstract
Epithelial cells have an apical surface facing a lumen or outside of the organism, and a basolateral surface facing other cells and extracellular matrix. The identity of the apical surface is determined by phosphatidylinositol 4,5-bisphosphate, while phosphatidylinositol 3,4,5-trisphophosphate determines the identity of the basolateral surface. The Par3/Par6/atypical protein kinase C complex, as well as the Crumbs and Scribble complexes, controls epithelial polarity. Par4 and AMP kinase regulate polarity during conditions of energy depletion. Lumens are formed in hollow cysts and tubules by fusions of apical vesicles, such as the vacuolar apical compartment, with the plasma membrane. The polarity of individual cells is oriented and coordinated with other cells by interactions with the extracellular matrix.
Collapse
|