Vinculin knockout results in heart and brain defects during embryonic development

Development ◽  
1998 ◽  
Vol 125 (2) ◽  
pp. 327-337 ◽  
Author(s):  
W. Xu ◽  
H. Baribault ◽  
E.D. Adamson
Keyword(s):  
Embryonic Development ◽  
Focal Adhesion ◽  
Heart Development ◽  
Cardiac Development ◽  
Es Cells ◽  
Embryonic Stem ◽  
Spinal Nerve ◽  
Cell Behaviors ◽  
Migration Rates ◽  
Targeting Vector

The vinculin gene codes for a cytoskeletal protein, found in focal adhesion plaques and in cell-cell adherens junctions. Vinculin was inactivated by homologous recombination using a targeting vector in embryonic stem (ES) cells. The heterozygous ES cells were introduced into mice by established procedures to produce heterozygous animals that were normal and fertile. No homozygous vinculin−/− embryos were born and analyses during the gestational period showed that the vinculin null embryos were small and abnormal from day E8 but some survived until E10. The most prominent defect was lack of midline fusion of the rostral neural tube, producing a cranial bilobular appearance and attenuation of cranial and spinal nerve development. Heart development was curtailed at E9.5, with severely reduced and akinetic myocardial and endocardial structures. Mutant embryos were 30–40% smaller, somites and limbs were retarded and ectodermal tissues were sparse and fragile. Fibroblasts (MEF) isolated from mutant embryos were shown to have reduced adhesion to fibronectin, vitronectin, laminin and collagen compared to wild-type levels. In addition, migration rates over these substrata were two-fold higher and the level of focal adhesion kinase (FAK) activity was three-fold higher. We conclude that vinculin is necessary for normal embryonic development, probably because of its role in the regulation of cell adhesion and locomotion, cell behaviors essential for normal embryonic morphogenesis, although specific roles in neural and cardiac development cannot be ruled out.

Abstract 1461: Wnt2 Plays a Key Role in Cardiac Development Via a Non-Canonical Pathway

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Takeshi Onizuka ◽  
Shinsuke Yuasa ◽  
Kenichiro Shimoji ◽  
Keiichi Fukuda ◽  
Satoshi Ogawa
Keyword(s):  
Heart Development ◽  
Cardiac Development ◽  
Early Stage ◽  
Es Cells ◽  
Embryonic Stem ◽  
Canonical Pathway ◽  
Embryonic Cells ◽  
Potent Effect ◽  
Canonical Wnt ◽  
Promising Source

Embryonic stem (ES) cells are a promising source of cardiomyocytes, but their clinical application has been hindered by the lack of selective differentiation methods. Although several signals are involved in heart development, the precise signals that mediate cardiomyocyte differentiation remain undetermined. Wnt family has a potent effect on the various organ development. To address this issue, we investigated the expression of wnt genes in the embryonic heart. Then we applied these findings to establish an efficient protocol to induce cardiomyocytes in vitro . (1) We analyzed TOP-EGFP mice to clarify whether canonical wnt signal pathway is important in the developing heart. TOP-EGFP mice are transgenic mice in which the EGFP gene is located under the β-catenin binding site so that the EGFP protein expresses when the canonical pathway is activated. They did not reveal any GFP in early stage heart, indicating that the canonical pathway is not involved. (2) Expression of non-canonical wnt was screened. Whole mount in situ hybridization of wnt2 and nkx2.5 (positive control) was performed at mouse embryo. Wnt2 was strongly expressed in the the heart-forming area in stages from E7.5 to E9.0. (3) We applied this embryonic wnt2 expression pattern to ES cell differentiation. Using siRNA we knocked-down wnt2 protein in various phases, which inhibited formation of beating EB, and decreased cardiac muscle genes only during the primitive stage (day 2– 4). Also adding wnt2 protein to embryonic cells in the appropriate phase led to a marked induction of cardiac specific genes. But wnt2 did not affect the mesodermal gene expression, Brachyury T and Mesp1, suggesting that Wnt2 does not affect the primitive development of the mesodermal progenitor cells. However, Wnt2 critically promotes cardiac specification after mesodermal induction and increases the eventual cardiac musculature. Wnt2 was strongly expressed in the heart-forming region. We applied this finding to develop an effective protocol for obtaining cardiomyocytes from mouse ES cells by adding wnt2 protein and also to inhibit generation of cardiomyocytes by inhibition of wnt2 signaling. We concluded that wnt2 plays a key role in cardiac development via a non-canonical pathway.

Germ line transmission of an inactive N-myc allele generated by homologous recombination in mouse embryonic stem cells

1990 ◽  
Vol 10 (12) ◽  
pp. 6755-6758
Author(s):  
B R Stanton ◽  
S W Reid ◽  
L F Parada
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Homologous Recombination ◽  
Embryonic Development ◽  
Cell Lines ◽  
Germ Line ◽  
Es Cells ◽  
Embryonic Stem ◽  
Es Cell ◽  
Germ Line Transmission

We have disrupted one allele of the N-myc locus in mouse embryonic stem (ES) cells by using homologous recombination techniques and have obtained germ line transmission of null N-myc ES cell lines with transmission of the null N-myc allele to the offspring. The creation of mice with a deficient N-myc allele will allow the generation of offspring bearing null N-myc alleles in both chromosomes and permit study of the role that this proto-oncogene plays in embryonic development.

Abstract 052: Epicardial-derived Adrenomedullin Drives Cardiac Hyperplasia During Embryogenesis

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Sarah E Wetzel-Strong ◽  
Manyu Li ◽  
Toshio Nishikimi ◽  
Kathleen M Caron
Keyword(s):  
Embryonic Development ◽  
Heart Development ◽  
Cardiac Development ◽  
Lymphatic Vessels ◽  
Heart Weight ◽  
Cardiovascular Development ◽  
Proliferating Cells ◽  
Over Expression ◽  
Knockout Animals

The multi-functional peptide adrenomedullin ( Adm = gene, AM = protein) plays important roles in embryonic development and disease. Previous studies demonstrated that Adm knockout mice die at embryonic day 13.5 with small, disorganized hearts and hypoplastic lymphatic vessels, highlighting the importance of this peptide in normal cardiovascular development. Since Adm knockout animals are embryonic lethal, our goal was to generate and characterize a novel model of Adm over-expression to study the role of Adm during development and disease processes. Through gene targeting techniques, we generated a novel mouse model of Adm over-expression, abbreviated as Adm hi/hi . When we assessed gene expression of Adm from 10 different tissues, we found Adm hi/hi mice express 3- to 15-fold more Adm than wildtype littermates. Additionally, peptide levels of AM in lung and kidney, as well as circulating plasma levels of AM were elevated 3-fold over wildtype mice, indicating a functional increase in AM. Our initial analysis revealed that adult Adm hi/hi mice have larger heart weight to body weight ratios than wildtype littermates (4.93±0.23 vs. 5.96±0.29, n = 11-12). We found that compared to wildtype, Adm hi/hi embryos have more proliferating cells during heart development (14.46±1.11 vs. 31.97±2.84, n=4), indicating that hyperplasia drives Adm hi/hi heart enlargement. By crossing the Adm hi/hi line to different tissue-specific Cre lines, we were able to excise the stabilizing bovine growth hormone 3’UTR, thereby returning Adm expression levels back to wildtype in cells with active Cre recombinase. Using this approach, we identified the epicardium as a major source of AM during cardiac development. In conclusion, we found that AM derived primarily from the epicardium drives cardiac hyperplasia during embryonic development resulting in persistent, enlarged hearts of adult Adm hi/hi mice. Since our Adm hi/hi mice recapitulate the 3-fold plasma elevation of AM observed during human disease, this mouse line will be a useful tool for studying the role of elevated AM during disease.

The cardiac homeobox gene Csx/Nkx2.5 lies genetically upstream of multiple genes essential for heart development

Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1269-1280 ◽  
Author(s):  
M. Tanaka ◽  
Z. Chen ◽  
S. Bartunkova ◽  
N. Yamasaki ◽  
S. Izumo
Keyword(s):  
Cardiac Myocytes ◽  
Heart Development ◽  
Cardiac Development ◽  
Es Cells ◽  
Homeobox Gene ◽  
Yolk Sac ◽  
Tunel Staining ◽  
Mesoderm Specification ◽  
Developing Heart ◽  
Heart Looping

Csx/Nkx2.5 is a vertebrate homeobox gene with a sequence homology to the Drosophila tinman, which is required for the dorsal mesoderm specification. Recently, heterozygous mutations of this gene were found to cause human congenital heart disease (Schott, J.-J., Benson, D. W., Basson, C. T., Pease, W., Silberbach, G. M., Moak, J. P., Maron, B. J., Seidman, C. E. and Seidman, J. G. (1998) Science 281, 108–111). To investigate the functions of Csx/Nkx2.5 in cardiac and extracardiac development in the vertebrate, we have generated and analyzed mutant mice completely null for Csx/Nkx2.5. Homozygous null embryos showed arrest of cardiac development after looping and poor development of blood vessels. Moreover, there were severe defects in vascular formation and hematopoiesis in the mutant yolk sac. Interestingly, TUNEL staining and PCNA staining showed neither enhanced apoptosis nor reduced cell proliferation in the mutant myocardium. In situ hybridization studies demonstrated that, among 20 candidate genes examined, expression of ANF, BNP, MLC2V, N-myc, MEF2C, HAND1 and Msx2 was disturbed in the mutant heart. Moreover, in the heart of adult chimeric mice generated from Csx/Nkx2.5 null ES cells, there were almost no ES cell-derived cardiac myocytes, while there were substantial contributions of Csx /Nkx2.5-deficient cells in other organs. Whole-mount β-gal staining of chimeric embryos showed that more than 20% contribution of Csx/Nkx2. 5-deficient cells in the heart arrested cardiac development. These results indicate that (1) the complete null mutation of Csx/Nkx2.5 did not abolish initial heart looping, (2) there was no enhanced apoptosis or defective cell cycle entry in Csx/Nkx2.5 null cardiac myocytes, (3) Csx/Nkx2.5 regulates expression of several essential transcription factors in the developing heart, (4) Csx/Nkx2.5 is required for later differentiation of cardiac myocytes, (5) Csx/Nkx2. 5 null cells exert dominant interfering effects on cardiac development, and (6) there were severe defects in yolk sac angiogenesis and hematopoiesis in the Csx/Nkx2.5 null embryos.

scholarly journals Serum response factor is crucial for actin cytoskeletal organization and focal adhesion assembly in embryonic stem cells

2002 ◽  
Vol 156 (4) ◽  
pp. 737-750 ◽  
Author(s):  
Gerhard Schratt ◽  
Ulrike Philippar ◽  
Jürgen Berger ◽  
Heinz Schwarz ◽  
Olaf Heidenreich ◽  
...  
Keyword(s):  
Focal Adhesion ◽  
Serum Response Factor ◽  
Es Cells ◽  
Embryonic Stem ◽  
Cell Spreading ◽  
Stress Fibers ◽  
Response Factor ◽  
Es Cell ◽  
And Migration ◽  
Serum Response

The activity of serum response factor (SRF), an essential transcription factor in mouse gastrulation, is regulated by changes in actin dynamics. Using Srf(−/−) embryonic stem (ES) cells, we demonstrate that SRF deficiency causes impairments in ES cell spreading, adhesion, and migration. These defects correlate with defective formation of cytoskeletal structures, namely actin stress fibers and focal adhesion (FA) plaques. The FA proteins FA kinase (FAK), β1-integrin, talin, zyxin, and vinculin were downregulated and/or mislocalized in ES cells lacking SRF, leading to inefficient activation of the FA signaling kinase FAK. Reduced overall actin expression levels in Srf(−/−) ES cells were accompanied by an offset treadmilling equilibrium, resulting in lowered F-actin levels. Expression of active RhoA-V14 rescued F-actin synthesis but not stress fiber formation. Introduction of constitutively active SRF-VP16 into Srf(−/−) ES cells, on the other hand, strongly induced expression of FA components and F-actin synthesis, leading to a dramatic reorganization of actin filaments into stress fibers and lamellipodia. Thus, using ES cell genetics, we demonstrate for the first time the importance of SRF for the formation of actin-directed cytoskeletal structures that determine cell spreading, adhesion, and migration. Our findings suggest an involvement of SRF in cell migratory processes in multicellular organisms.

scholarly journals A Rapid and Highly Efficient Genotyping Pipeline for Screening Gene Targeted Mouse Embryonic Stem Cells

2021 ◽  
Author(s):  
Roger Caothien ◽  
Charles Yu ◽  
Lucinda Tam ◽  
Robert Newman ◽  
Brian Nakao ◽  
...  
Keyword(s):  
Animal Models ◽  
Gene Targeting ◽  
Fluorescent Protein ◽  
Es Cells ◽  
Expression Patterns ◽  
Embryonic Stem ◽  
Rapid Screening ◽  
Es Cell ◽  
Screening Process ◽  
Targeting Vector

Abstract Gene targeting in mouse ES cells replaces or modifies genes of interest; conditional alleles, reporter knock-ins, and amino acid changes are common examples of how gene targeting is used. For example, enhanced green fluorescent protein or Cre recombinase is placed under the control of endogenous genes to define promoter expression patterns. The most important step in the process is to demonstrate that a gene targeting vector is correctly integrated in the genome at the desired chromosomal location. The rapid identification of correctly targeted ES cell clones is facilitated by proper targeting vector construction, rapid screening procedures, and advances in cell culture. The addition of magnetic activated cell sorting (MACS) technology and multiplex droplet digital PCR (ddPCR) to the ES cell screening process can achieve a greater than 60% assurance that ES clones are correctly targeted. In a further refinement of the process, drug selection cassettes are removed from ES cells with adenovirus technology. This improved workflow reduces the time needed to generate preclinical animal models. Faster access to animal models for therapeutic target identification and experimental validation can accelerate the development of therapies for human disease.

scholarly journals Transcriptome and DNA Methylome Dynamics during Triclosan-Induced Cardiomyocyte Differentiation Toxicity

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Guizhen Du ◽  
Mingming Yu ◽  
Lingling Wang ◽  
Weiyue Hu ◽  
Ling Song ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Heart Development ◽  
Antibacterial Agent ◽  
Human Embryonic Stem Cell ◽  
Cardiac Development ◽  
Embryonic Stem ◽  
Environmental Chemicals ◽  
Cardiomyocyte Differentiation ◽  
Gene Expressions ◽  
Gata Motif

Cardiac development is a dynamic process and sensitive to environmental chemicals. Triclosan is widely used as an antibacterial agent and reported to transport across the placenta and affect embryonic development. Here, we used human embryonic stem cell- (hESC-) derived cardiomyocytes (CMs) to determine the effects of TCS exposure on cardiac development. After TCS treatment, the differentiation process was significantly blocked and spontaneous beating rates of CMs were also decreased. Transcriptome analysis showed the dysregulation of genes involved in cardiogenesis, including GATA4 and TNNT2. Additionally, DNA methylation was also altered by TCS exposure, especially in those regions with GATA motif enrichment. These alterations of transcriptome and DNA methylation were all associated with signaling pathways integral to heart development. Our findings indicate that TCS exposure might cause cardiomyocyte differentiation toxicity and provide the new insights into how environmental factors regulate DNA methylation and gene expressions during heart development.

scholarly journals Germ line transmission of an inactive N-myc allele generated by homologous recombination in mouse embryonic stem cells.

1990 ◽  
Vol 10 (12) ◽  
pp. 6755-6758 ◽  
Author(s):  
B R Stanton ◽  
S W Reid ◽  
L F Parada
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Homologous Recombination ◽  
Embryonic Development ◽  
Cell Lines ◽  
Germ Line ◽  
Es Cells ◽  
Embryonic Stem ◽  
Es Cell ◽  
Germ Line Transmission

We have disrupted one allele of the N-myc locus in mouse embryonic stem (ES) cells by using homologous recombination techniques and have obtained germ line transmission of null N-myc ES cell lines with transmission of the null N-myc allele to the offspring. The creation of mice with a deficient N-myc allele will allow the generation of offspring bearing null N-myc alleles in both chromosomes and permit study of the role that this proto-oncogene plays in embryonic development.

scholarly journals Dp1 Is Largely Dispensable for Embryonic Development

2004 ◽  
Vol 24 (16) ◽  
pp. 7197-7205 ◽  
Author(s):  
Matthew J. Kohn ◽  
Sandra W. Leung ◽  
Vittoria Criniti ◽  
Monica Agromayor ◽  
Lili Yamasaki
Keyword(s):  
Cell Cycle ◽  
Embryonic Development ◽  
Cell Cycle Progression ◽  
Target Genes ◽  
Es Cells ◽  
Embryonic Stem ◽  
Wild Type ◽  
Cycle Progression ◽  
Cell Cycle Genes

ABSTRACT E2F/DP complexes activate or repress the transcription of E2F target genes, depending on the association of a pRB family member, thereby regulating cell cycle progression. Whereas the E2F family consists of seven members, the DP family contains only two (Dp1 and Dp2), Dp1 being the more highly expressed member. In contrast to the inactivation of individual E2F family members, we have recently demonstrated that loss of Dp1 results in embryonic lethality by embryonic day 12.5 (E12.5) due to the failure of extraembryonic lineages to develop and replicate DNA properly. To bypass this placental requirement and search for roles of Dp1 in the embryo proper, we generated Dp1-deficient embryonic stem (ES) cells that carry the ROSA26-LacZ marker and injected them into wild-type blastocysts to construct Dp1-deficient chimeras. Surprisingly, we recovered mid- to late gestational embryos (E12.5 to E17.5), in which the Dp1-deficient ES cells contributed strongly to most chimeric tissues as judged by X-Gal (5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside) staining and Western blotting. Importantly, the abundance of DP2 protein does not increase and the expression of an array of cell cycle genes is virtually unchanged in Dp1-deficient ES cells or chimeric E15.5 tissues with the absence of Dp1. Thus, Dp1 is largely dispensable for embryonic development, despite the absolute extraembryonic requirement for Dp1, which is highly reminiscent of the restricted roles for Rb and cyclins E1/E2 in vivo.

scholarly journals 170 ASSESSING THE POTENTIAL OF STEM CELLS TO GENERATE CHIMERIC RATS

2005 ◽  
Vol 17 (2) ◽  
pp. 236
Author(s):  
J. Guo ◽  
S. Fida ◽  
K. Gou ◽  
C. Zhang ◽  
J. Morrison ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Development ◽  
Neural Stem Cells ◽  
Embryo Transfer ◽  
Coat Color ◽  
Es Cells ◽  
Embryonic Stem ◽  
Dark Agouti ◽  
Inbred Rat ◽  
Lac Z

Embryonic stem (ES) cells are pluripotent cells derived from inner cell masses (ICMs) of blastocysts. The capacity of pluripotency in differentiation is assumed to contribute to embryonic development to form a chimeric individual when these cells are reintroduced into embryos. Chimeric mice can be routinely generated by aggregation of ES cells with morulae or injection into blastocysts, which are then implanted in pseudopregnant foster mothers. Furthermore, recent studies have demonstrated that bone marrow-derived stem cells and neural stem cells can integrate into the embryonic development in mouse (Geiger et al. 1998 Cell 93, 1055–1065; Clarke et al. 2000 Science 288, 1660–1663). We therefore tried to assess the ability of rat ICMs and neural stem cells to form chimeras by injecting these cells into rat blastocysts. Forty-two rat ICMs from Day 6 blastocysts of Dark Agouti (DA) inbred rat were injected into Day 5 blastocysts of Sprague-Dawleyd (SD) outbred rats; 14 pups were born following embryo transfer of these blastocysts injected into Hooded Wistar (HW) recipients. One male of the 14 pups was coat color-patched and displayed germline transmission. Following embryo transfer of 22 SD blastocysts injected by Day 5 DA ICMs, 7 pups were born and 2 of them were coat color-patched. Nine pups were obtained from 23 DA blastocysts injected by Day 5 SD ICMs; 4 of them were coat color-patched. The ICM cells were isolated and cultured for 6 days. No chimeras were generated by injection of the cultured ICM cells, as assessed by coat color patching. These results suggest that rat embryonic ICMs have potential to develop into chimeras, but the chimeric potential of ICMs was rapidly lost in our culture system. Investigation of potential chimeric development of rat fetal neural stem (rFNS) cells transfected with Lac Z was carried out. Staining was observed in tissues from 2 of 41 E14 fetuses. These results demonstrated that rFNS cells can integrate into the early embryonic environment although the ability of these cells to contribute to chimeric formation was marginal. No coat color chimerism was observed in any of the 88 pups generated from the LacZ-rFNS cell experiments.

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