Gene Expression Analysis of Mouse Embryonic Stem Cells Following Levitation in an Ultrasound Standing Wave Trap

PubMed Central

Bazou, Despina; Kearney, Roisin; Mansergh, Fiona; Bourdon, Celine; Farrar, Jane; Wride, Michael

2011-01-01

In the present paper, gene expression analysis of mouse embryonic stem (ES) cells levitated in a novel ultrasound standing wave trap (USWT) (Bazou et al. 2005a) at variable acoustic pressures (0.08–0.85 MPa) and times (5–60 min) was performed. Our results showed that levitation of ES cells at the highest employed acoustic pressure for 60 min does not modify gene expression and cells maintain their pluripotency. Embryoid bodies (EBs) also expressed the early and late neural differentiation markers, which were also unaffected by the acoustic field. Our results suggest that the ultrasound trap microenvironment is minimally invasive as the biologic consequences of ES cell replication and EB differentiation proceed without significantly affecting gene expression. The technique holds great promise in safe cell manipulation techniques for a variety of applications including tissue engineering and regenerative medicine. (E-mail: Bazoud@tcd.ie) PMID:21208732

Exogenous transforming growth factor-β1 enhances smooth muscle differentiation in embryonic mouse jejunal explants.

PubMed

Coletta, Riccardo; Roberts, Neil A; Randles, Michael J; Morabito, Antonino; Woolf, Adrian S

2017-01-13

An ex vivo experimental strategy that replicates in vivo intestinal development would in theory provide an accessible setting with which to study normal and dysmorphic gut biology. The current authors recently described a system in which mouse embryonic jejunal segments were explanted onto semipermeable platforms and fed with chemically defined serum-free media. Over 3 days in organ culture, explants formed villi and they began to undergo spontaneous peristalsis. As defined in the current study, the wall of the explanted gut failed to form a robust longitudinal smooth muscle (SM) layer as it would do in vivo over the same time period. Given the role of transforming growth factor β1 (TGFβ1) in SM differentiation in other organs, it was hypothesized that exogenous TGFβ1 would enhance SM differentiation in these explants. In vivo, TGFβ receptors I and II were both detected in embryonic longitudinal jejunal SM cells and, in organ culture, exogenous TGFβ1 induced robust differentiation of longitudinal SM. Microarray profiling showed that TGFβ1 increased SM specific transcripts in a dose dependent manner. TGFβ1 proteins were detected in amniotic fluid at a time when the intestine was physiologically herniated. By analogy with the requirement for exogenous TGFβ1 for SM differentiation in organ culture, the TGFβ1 protein that was demonstrated to be present in the amniotic fluid may enhance intestinal development when it is physiologically herniated in early gestation. Future studies of embryonic intestinal cultures should include TGFβ1 in the defined media to produce a more faithful model of in vivo muscle differentiation. Copyright © 2017 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd. Copyright © 2017 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd.

Gelatin-based microcarriers as embryonic stem cell delivery system in bone tissue engineering: an in-vitro study.

PubMed

Tielens, S; Declercq, H; Gorski, T; Lippens, E; Schacht, E; Cornelissen, M

2007-03-01

Mouse embryonic stem cells were cultured on commercially available biodegradable macroporous microcarriers. A culture period of 1-2 weeks was needed to colonize the microcarriers. Embryonic stem cells retained their pluripotency for up to 14 days when cultured in medium supplemented with leukemia inhibitory factor. Replacing this medium by differentiation medium for 2 weeks initiated osteogenic differentiation. Encapsulation of the cell-loaded microcarriers in photopolymerizable polymers (methacrylate-endcapped poly-D,L-lactide-co-caprolactone), triacetin/hydroxyethylmethacrylate (HEMA) as solvent and with/without gelatin as porogen, resulted in a homogeneous distribution of the microcarriers in the polymer. As observed by transmission electron microscopy, viability of the cells was optimal when gelatin was omitted and when using triacetin instead of HEMA.

Genome engineering via homologous recombination in mouse embryonic stem (ES) cells: an amazingly versatile tool for the study of mammalian biology.

PubMed

Babinet, C; Cohen-Tannoudji, M

2001-09-01

The ability to introduce genetic modifications in the germ line of complex organisms has been a long-standing goal of those who study developmental biology. In this regard, the mouse, a favorite model for the study of the mammals, is unique: indeed not only is it possible since the late seventies, to add genes to the mouse genome like in several other complex organisms but also to perform gene replacement and modification. This has been made possible via two technological breakthroughs: 1) the isolation and culture of embryonic stem cells (ES), which have the unique ability to colonize all the tissues of an host embryo including its germ line; 2) the development of methods allowing homologous recombination between an incoming DNA and its cognate chromosomal sequence (gene "targeting"). As a result, it has become possible to create mice bearing null mutations in any cloned gene (knock-out mice). Such a possibility has revolutionized the genetic approach of almost all aspects of the biology of the mouse. In recent years, the scope of gene targeting has been widened even more, due to the refinement of the knock-out technology: other types of genetic modifications may now be created, including subtle mutations (point mutations, micro deletions or insertions, etc.) and chromosomal rearrangements such as large deletions, duplications and translocations. Finally, methods have been devised which permit the creation of conditional mutations, allowing the study of gene function throughout the life of an animal, when gene inactivation entails embryonic lethality. In this paper, we present an overview of the methods and scenarios used for the programmed modification of mouse genome, and we underline their enormous interest for the study of mammalian biology.

In utero imaging of mouse embryonic development with optical coherence tomography

NASA Astrophysics Data System (ADS)

Syed, Saba H.; Dickinson, Mary E.; Larin, Kirill V.; Larina, Irina V.

2011-03-01

Studying progression of congenital diseases in animal models can greatly benefit from live embryonic imaging Mouse have long served as a model of mammalian embryonic developmental processes, however, due to intra-uterine nature of mammalian development live imaging is challenging. In this report we present results on live mouse embryonic imaging in utero with Optical Coherence Tomography. Embryos from 12.5 through 17.5 days post-coitus (dpc) were studied through the uterine wall. In longitudinal studies, same embryos were imaged at developmental stages 13.5, 15.5 and 17.5 dpc. This study suggests that OCT can serve as a powerful tool for live mouse embryo imaging. Potentially this technique can contribute to our understanding developmental abnormalities associated with mutations, toxic drugs.

Concentration dependent survival and neural differentiation of murine embryonic stem cells cultured on polyethylene glycol dimethacrylate hydrogels possessing a continuous concentration gradient of n-cadherin derived peptide His-Ala-Val-Asp-Lle.

PubMed

Lim, Hyun Ju; Mosley, Matthew C; Kurosu, Yuki; Smith Callahan, Laura A

2017-07-01

N-cadherin cell-cell signaling plays a key role in the structure and function of the nervous system. However, few studies have incorporated bioactive signaling from n-cadherin into tissue engineering matrices. The present study uses a continuous gradient approach in polyethylene glycol dimethacrylate hydrogels to identify concentration dependent effects of n-cadherin peptide, His-Ala-Val-Asp-Lle (HAVDI), on murine embryonic stem cell survival and neural differentiation. The n-cadherin peptide was found to affect the expression of pluripotency marker, alkaline phosphatase, in murine embryonic stem cells cultured on n-cadherin peptide containing hydrogels in a concentration dependent manner. Increasing n-cadherin peptide concentrations in the hydrogels elicited a biphasic response in neurite extension length and mRNA expression of neural differentiation marker, neuron-specific class III β-tubulin, in murine embryonic stem cells cultured on the hydrogels. High concentrations of n-cadherin peptide in the hydrogels were found to increase the expression of apoptotic marker, caspase 3/7, in murine embryonic stem cells compared to that of murine embryonic stem cell cultures on hydrogels containing lower concentrations of n-cadherin peptide. Increasing the n-cadherin peptide concentration in the hydrogels facilitated greater survival of murine embryonic stem cells exposed to increasing oxidative stress caused by hydrogen peroxide exposure. The combinatorial approach presented in this work demonstrates concentration dependent effects of n-cadherin signaling on mouse embryonic stem cell behavior, underscoring the need for the greater use of systematic approaches in tissue engineering matrix design in order to understand and optimize bioactive signaling in the matrix for tissue formation. Single cell encapsulation is common in tissue engineering matrices. This eliminates cellular access to cell-cell signaling. N-cadherin, a cell-cell signaling molecule, plays a vital role in the development of neural tissues, but has not been well studied as a bioactive signaling element in neural tissue engineering matrices. The present study uses a systematic continuous gradient approach to identify concentration dependent effects of n-cadherin derived peptide, HAVDI, on the survival and neural differentiation of murine embryonic stem cells. This work underscores the need for greater use to combinatorial strategies to understand the effect complex bioactive signaling, such as n-cadherin, and the need to optimize the concentration of such bioactive signaling within tissue engineering matrices for maximal cellular response. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay

EPA Science Inventory

The Embryonic Stem Cell Test (EST) is an assay which evaluates xenobiotic-induced effects using three endpoints: mouse embryonic stem cell (mESC) differentiation, mESC viability, and 3T3-cell viability. Our research goal was to develop an improved high-throughput assay by establi...

Reprogrammed mouse astrocytes retain a "memory" of tissue origin and possess more tendencies for neuronal differentiation than reprogrammed mouse embryonic fibroblasts.

PubMed

Tian, Changhai; Wang, Yongxiang; Sun, Lijun; Ma, Kangmu; Zheng, Jialin C

2011-02-01

Direct reprogramming of a variety of somatic cells with the transcription factors Oct4 (also called Pou5f1), Sox2 with either Klf4 and Myc or Lin28 and Nanog generates the induced pluripotent stem cells (iPSCs) with marker similarity to embryonic stem cells. However, the difference between iPSCs derived from different origins is unclear. In this study, we hypothesized that reprogrammed cells retain a "memory" of their origins and possess additional potential of related tissue differentiation. We reprogrammed primary mouse astrocytes via ectopic retroviral expression of OCT3/4, Sox2, Klf4 and Myc and found the iPSCs from mouse astrocytes expressed stem cell markers and formed teratomas in SCID mice containing derivatives of all three germ layers similar to mouse embryonic stem cells besides semblable morphologies. To test our hypothesis, we compared embryonic bodies (EBs) formation and neuronal differentiation between iPSCs from mouse embryonic fibroblasts (MEFsiPSCs) and iPSCs from mouse astrocytes (mAsiPSCs). We found that mAsiPSCs grew slower and possessed more potential for neuronal differentiation compared to MEFsiPSCs. Our results suggest that mAsiPSCs retain a "memory" of the central nervous system, which confers additional potential upon neuronal differentiation.

Generation of Corneal Keratocytes from Human Embryonic Stem Cells.

PubMed

Hertsenberg, Andrew J; Funderburgh, James L

2016-01-01

Human Embryonic Stem Cells (hESC) offer an important resource as a limitless supply of any differentiated cell type of the human body. Keratocytes, cells from the corneal stroma, may have the potential for restoration of vision in cell therapy and biomedical engineering applications, but these specialized cells are not readily expanded in vitro. Here we describe a two-part method to produce keratocytes from the H1 hESC cell line. The hESC cells, maintained and expanded in feeder-free culture medium are first differentiated to neural crest cells using the stromal-derived inducing activity (SDIA) of the PA6 mouse embryonic fibroblast cell line. The resulting neural crest cells are selected by their expression of cell-surface CD271 and subsequently cultured as 3D pellets in a defined differentiation medium to induce a keratocyte phenotype.

HUPO BPP pilot study: a proteomics analysis of the mouse brain of different developmental stages.

PubMed

Wang, Jing; Gu, Yong; Wang, Lihong; Hang, Xingyi; Gao, Yan; Wang, Hangyan; Zhang, Chenggang

2007-11-01

This study is a part of the HUPO Brain Proteome Project (BPP) pilot study, which aims at obtaining a reliable database of mouse brain proteome, at the comparison of techniques, laboratories, and approaches as well as at preparing subsequent proteome studies of neurologic diseases. The C57/Bl6 mouse brains of three developmental stages at embryonic day 16 (E16), postnatal day 7 (P7), and 8 wk (P56) (n = 5 in each group) were provided by the HUPO BPP executive committee. The whole brain proteins of each animal were individually prepared using 2-DE coupled with PDQuest software analysis. The protein spots representing developmentally related or stably expressed proteins were then prepared with in-gel digestion followed with MALDI-TOF/TOF MS/MS and analyzed using the MASCOT search engines to search the Swiss-Prot or NCBInr database. The 2-DE gel maps of the mouse brains of all of the developmental stages were obtained and submitted to the Data Collection Centre (DCC). The proteins alpha-enolase, stathmin, actin, C14orf166 homolog, 28,000 kDa heat- and acid-stable phosphoprotein, 3-mercaptopyruvate sulfurtransferase and 40 S ribosomal protein S3a were successfully identified. A further Western blotting analysis demonstrated that enolase is a protein up-regulated in the mouse brain from embryonic stage to adult stage. These data are helpful for understanding the proteome changes in the development of the mouse brain.

Fluorescence lifetime imaging of induced pluripotent stem cells

NASA Astrophysics Data System (ADS)

Uchugonova, Aisada; Batista, Ana; König, Karsten

2014-02-01

The multiphoton FLIM tomograph MPTflex with its flexible scan head, articulated arm, and the tunable femtosecond laser source was employed to study cell monolayers and 3D cell clusters. FLIM was performed with 250 ps temporal resolution and submicron special resolution using time-correlated single photon counting. The autofluorescence based on NAD(P)H and flavins/flavoproteins has been measured in mouse embryonic fibroblasts, induced pluripotent stem cells (iPS cells) originated from mouse embryonic fibroblasts and non-proliferative mouse embryonic fibroblasts.

Establishment of mouse embryonic stem cells from isolated blastomeres and whole embryos using three derivation methods

PubMed Central

González, Sheyla; Ibáñez, Elena

2010-01-01

Purpose The aim of the present study is to compare three previously described mouse embryonic stem cell derivation methods to evaluate the influence of culture conditions, number of isolated blastomeres and embryonic stage in the derivation process. Methods Three embryonic stem cell derivation methods: standard, pre-adhesion and defined culture medium method, were compared in the derivation from isolated blastomeres and whole embryos at 4- and 8-cell stages. Results A total of 200 embryonic stem cell lines were obtained with an efficiency ranging from 1.9% to 72%. Conclusions Using either isolated blastomeres or whole embryos, the highest rates of mouse embryonic stem cell establishment were achieved with the defined culture medium method and efficiencies increased as development progressed. Using isolated blastomeres, efficiencies increased in parallel to the proportion of the embryo volume used to start the derivation process. PMID:20862536

Gene expression analysis of mouse embryonic stem cells following levitation in an ultrasound standing wave trap.

PubMed

Bazou, Despina; Kearney, Roisin; Mansergh, Fiona; Bourdon, Celine; Farrar, Jane; Wride, Michael

2011-02-01

In the present paper, gene expression analysis of mouse embryonic stem (ES) cells levitated in a novel ultrasound standing wave trap (USWT) (Bazou et al. 2005a) at variable acoustic pressures (0.08-0.85 MPa) and times (5-60 min) was performed. Our results showed that levitation of ES cells at the highest employed acoustic pressure for 60 min does not modify gene expression and cells maintain their pluripotency. Embryoid bodies (EBs) also expressed the early and late neural differentiation markers, which were also unaffected by the acoustic field. Our results suggest that the ultrasound trap microenvironment is minimally invasive as the biologic consequences of ES cell replication and EB differentiation proceed without significantly affecting gene expression. The technique holds great promise in safe cell manipulation techniques for a variety of applications including tissue engineering and regenerative medicine. Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Development of an invitro technique to use mouse embryonic stem cell in evaluating effects of xenobiotics

EPA Science Inventory

Our goal has been to develop a high-throughput, in vitro technique for evaluating the effects of xenobiotics using mouse embryonic stem cells (mESCs). We began with the Embryonic Stem Cell Test (EST), which is used to predict the embryotoxic potential of a test compound by combin...

Rotational imaging optical coherence tomography for full-body mouse embryonic imaging

PubMed Central

Wu, Chen; Sudheendran, Narendran; Singh, Manmohan; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

2016-01-01

Abstract. Optical coherence tomography (OCT) has been widely used to study mammalian embryonic development with the advantages of high spatial and temporal resolutions and without the need for any contrast enhancement probes. However, the limited imaging depth of traditional OCT might prohibit visualization of the full embryonic body. To overcome this limitation, we have developed a new methodology to enhance the imaging range of OCT in embryonic day (E) 9.5 and 10.5 mouse embryos using rotational imaging. Rotational imaging OCT (RI-OCT) enables full-body imaging of mouse embryos by performing multiangle imaging. A series of postprocessing procedures was performed on each cross-section image, resulting in the final composited image. The results demonstrate that RI-OCT is able to improve the visualization of internal mouse embryo structures as compared to conventional OCT. PMID:26848543

Induction of ICAM-1 Expression in Mouse Embryonic Fibroblasts Cultured on Fibroin-Gelatin Scaffolds

PubMed Central

Nosenko, M. A.; Maluchenko, N. V.; Drutskaya, M. S.; Arkhipova, A. Y.; Agapov, I. I.; Nedospasov, S. A.; Moisenovich, M. M.

2017-01-01

Culturing of allogeneic or autologous cells in three-dimensional bioresorbable scaffolds is an important step in the engineering of constructs for regenerative medicine, as well as for experimental systems to study the mechanisms of cell differentiation and cell-to-cell interaction. Artificial substrates can modulate the phenotype and functional activity of immobilized cells. Investigating these changes is important for understanding the fundamental processes underlying cellular interactions in a 3D microenvironment and for improving tissue-engineered structures. In this study, we investigated the expression of the ICAM-1 adhesion molecule in mouse embryonic fibroblasts (MEF) when cultured on gelatin-fibroin scaffolds. Increased expression of ICAM-1 in MEF was detected only under 3D culture conditions both at the mRNA and protein levels. At the same time, the MEF cultured on various substrates did not oerexpress MAdCAM-1, indicating the selective effect of 3D culture conditions on ICAM-1 expression. One possible mechanism for ICAM-1 induction in MEF is associated with the activation of AP-1, since expression of c-Fos and Junb (but not cJun and Jund) was increased in MEF in 3D. When cultured under 2D conditions, the expression level of AP-1 components did not change. PMID:29104780

Embryoid bodies formation and differentiation from mouse embryonic stem cells in collagen/Matrigel scaffolds.

PubMed

Zhou, Jin; Zhang, Ye; Lin, Qiuxia; Liu, Zhiqiang; Wang, Haibin; Duan, Cuimi; Wang, Yanmeng; Hao, Tong; Wu, Kuiwu; Wang, Changyong

2010-07-01

Embryonic stem (ES) cells have the potential to develop into any type of tissue and are considered as a promising source of seeding cells for tissue engineering and transplantation therapy. The main catalyst for ES cells differentiation is the growth into embryoid bodies (EBs), which are utilized widely as the trigger of in vitro differentiation. In this study, a novel method for generating EBs from mouse ES cells through culture in collagen/Matrigel scaffolds was successfully established. When single ES cells were seeded in three dimensional collagen/Matrigel scaffolds, they grew into aggregates gradually and formed simple EBs with circular structures. After 7 days' culture, they formed into cystic EBs that would eventually differentiate into the three embryonic germ layers. Evaluation of the EBs in terms of morphology and potential to differentiate indicated that they were typical in structure and could generate various cell types; they were also able to form into tissue-like structures. Moreover, with introduction of ascorbic acid, ES cells differentiated into cardiomyocytes efficiently and started contracting synchronously at day 19. The results demonstrated that collagen/Matrigel scaffolds supported EBs formation and their subsequent differentiation in a single three dimensional environment. Copyright 2010 Institute of Genetics and Developmental Biology and the Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

Different effects of enhanced and reduced expression of pub gene on the formation of embryoid bodies by cultured embryonic mouse stem cell.

PubMed

Novosadova, E V; Manuilova, E S; Arsen'eva, E L; Khaidarova, N V; Dolotov, O V; Inozemtseva, L S; Kozachenkov, K Yu; Tarantul, V Z; Grivennikov, I A

2005-07-01

The effects of pub gene on proliferation and initial stages of differentiation of embryonic mouse stem cells were studied in vitro. To this end we used enhanced expression of human pub gene (hpub) and suppression of expression of mouse endogenous pub gene with RNA-interference in embryonic stem cells. Proliferative activity of genetically modified polyclonal lines of the embryonic stem cells transfected with plasmids carrying expressing hpub gene or plasmids generating small interference RNA to this gene did not differ from that of the control cells. Inhibition of expression of endogenous pub gene in embryonic stem cells using small interference RNA 2-fold decreased the formation of embryoid bodies, at the same time additional expression of exogenous hpub gene almost 2-fold increased their number in comparison with the control. It was hypothesized that pub gene participates in early stages of differentiation of embryonic stem cells leading to the formation of embryoid bodies.

Identification and functional analysis of long non-coding RNAs in human and mouse early embryos based on single-cell transcriptome data

PubMed Central

Qiu, Jia-jun; Ren, Zhao-rui; Yan, Jing-bin

2016-01-01

Epigenetics regulations have an important role in fertilization and proper embryonic development, and several human diseases are associated with epigenetic modification disorders, such as Rett syndrome, Beckwith-Wiedemann syndrome and Angelman syndrome. However, the dynamics and functions of long non-coding RNAs (lncRNAs), one type of epigenetic regulators, in human pre-implantation development have not yet been demonstrated. In this study, a comprehensive analysis of human and mouse early-stage embryonic lncRNAs was performed based on public single-cell RNA sequencing data. Expression profile analysis revealed that lncRNAs are expressed in a developmental stage–specific manner during human early-stage embryonic development, whereas a more temporal-specific expression pattern was identified in mouse embryos. Weighted gene co-expression network analysis suggested that lncRNAs involved in human early-stage embryonic development are associated with several important functions and processes, such as oocyte maturation, zygotic genome activation and mitochondrial functions. We also found that the network of lncRNAs involved in zygotic genome activation was highly preservative between human and mouse embryos, whereas in other stages no strong correlation between human and mouse embryo was observed. This study provides insight into the molecular mechanism underlying lncRNA involvement in human pre-implantation embryonic development. PMID:27542205

High-Frequency Ultrasound for the Study of Early Mouse Embryonic Cardiovascular System.

PubMed

Greco, Adelaide; Coda, Anna Rita Daniela; Albanese, Sandra; Ragucci, Monica; Liuzzi, Raffaele; Auletta, Luigi; Gargiulo, Sara; Lamagna, Francesco; Salvatore, Marco; Mancini, Marcello

2015-12-01

An accurate diagnosis of congenital heart defects during fetal development is critical for interventional planning. Mice can be used to generate animal models with heart defects, and high-frequency ultrasound (HFUS) imaging enables in utero imaging of live mouse embryos. A wide range of physiological measurements is possible using Doppler-HFUS imaging; limitations of any single measurement warrant a multiparameter approach to characterize cardiovascular function. Doppler-HFUS was used to explore the embryonic (heart, aorta) and extraembryonic (umbilical blood flow) circulatory systems to create a database in normal mouse embryos between 9.5 and 16.5 days of gestation. Multivariate analyses were performed to explore correlations between gestational age and embryo echocardiographic parameters. Heart rate and peak velocity in the aorta were positively correlated with gestational time, whereas cardiac cycle length, isovolumetric relaxation time, myocardial performance index, and arterial deceleration time of the umbilical cord were negatively correlated with it. Doppler-HFUS facilitated detailed characterization of the embryonic mouse circulation and represents a useful tool for investigation of the early mouse embryonic cardiovascular system. © The Author(s) 2015.

Live dynamic OCT imaging of cardiac structure and function in mouse embryos with 43 Hz direct volumetric data acquisition

NASA Astrophysics Data System (ADS)

Wang, Shang; Singh, Manmohan; Lopez, Andrew L.; Wu, Chen; Raghunathan, Raksha; Schill, Alexander; Li, Jiasong; Larin, Kirill V.; Larina, Irina V.

2016-03-01

Efficient phenotyping of cardiac dynamics in live mouse embryos has significant implications on understanding of early mammalian heart development and congenital cardiac defects. Recent studies established optical coherence tomography (OCT) as a powerful tool for live embryonic heart imaging in various animal models. However, current four-dimensional (4D) OCT imaging of the beating embryonic heart largely relies on gated data acquisition or postacquisition synchronization, which brings errors when cardiac cycles lack perfect periodicity and is time consuming and computationally expensive. Here, we report direct 4D OCT imaging of the structure and function of cardiac dynamics in live mouse embryos achieved by employing a Fourier domain mode-locking swept laser source that enables ~1.5 MHz A-line rate. Through utilizing both forward and backward scans of a resonant mirror, we obtained a ~6.4 kHz frame rate, which allows for a direct volumetric data acquisition speed of ~43 Hz, around 20 times of the early-stage mouse embryonic heart rate. Our experiments were performed on mouse embryos at embryonic day 9.5. Time-resolved 3D cardiodynamics clearly shows the heart structure in motion. We present analysis of cardiac wall movement and its velocity from the primitive atrium and ventricle. Our results suggest that the combination of ultrahigh-speed OCT imaging with live embryo culture could be a useful embryonic heart phenotyping approach for mouse mutants modeling human congenital heart diseases.

Establishment of mouse expanded potential stem cells

PubMed Central

Gao, Xuefei; Antunes, Liliana; Yu, Yong; Zhu, Zhexin; Wang, Juexuan; Kolodziejczyk, Aleksandra A.; Campos, Lia S.; Wang, Cui; Yang, Fengtang; Zhong, Zhen; Fu, Beiyuan; Eckersley-Maslin, Melanie A.; Woods, Michael; Tanaka, Yosuke; Chen, Xi; Wilkinson, Adam C.; Bussell, James; White, Jacqui; Ramirez-Solis, Ramiro; Reik, Wolf; Göttgens, Berthold; Teichmann, Sarah A.; Tam, Patrick P. L.; Nakauchi, Hiromitsu; Zou, Xiangang; Lu, Liming; Liu, Pentao

2018-01-01

Mouse embryonic stem cells derived from the epiblast1 contribute to the somatic lineages and the germline but are excluded from the extra-embryonic tissues that are derived from the trophectoderm and the primitive endoderm2 upon reintroduction to the blastocyst. Here we report that cultures of expanded potential stem cells can be established from individual eight-cell blastomeres, and by direct conversion of mouse embryonic stem cells and induced pluripotent stem cells. Remarkably, a single expanded potential stem cell can contribute both to the embryo proper and to the trophectoderm lineages in a chimaera assay. Bona fide trophoblast stem cell lines and extra-embryonic endoderm stem cells can be directly derived from expanded potential stem cells in vitro. Molecular analyses of the epigenome and single-cell transcriptome reveal enrichment for blastomere-specific signature and a dynamic DNA methylome in expanded potential stem cells. The generation of mouse expanded potential stem cells highlights the feasibility of establishing expanded potential stem cells for other mammalian species. PMID:29019987

Complete TCRα gene locus control region activity in T cells derived in vitro from embryonic stem cells

PubMed Central

Lahiji, Armin; Kučerová-Levisohn, Martina; Lovett, Jordana; Holmes, Roxanne; Zúñiga-Pflücker, Juan Carlos; Ortiz, Benjamin D.

2013-01-01

Locus Control Regions (LCR) are cis-acting gene regulatory elements with the unique, integration site-independent ability to transfer the characteristics of their locus-of-origin’s gene expression pattern to a linked transgene in mice. LCR activities have been discovered in numerous T cell lineage expressed gene loci. These elements can be adapted to the design of stem cell gene therapy vectors that direct robust therapeutic gene expression to the T cell progeny of engineered stem cells. Currently, transgenic mice provide the only experimental approach that wholly supports all the critical aspects of LCR activity. Herein we report manifestation of all key features of mouse T cell receptor (TCR)-α gene LCR function in T cells derived in vitro from mouse embryonic stem cells (ESC). High level, copy number-related TCRα LCR-linked reporter gene expression levels are cell type-restricted in this system, and upregulated during the expected stage transition of T cell development. We further report that de novo introduction of TCRα LCR linked transgenes into existing T cell lines yields incomplete LCR activity. Together, these data indicate that establishing full TCRα LCR activity requires critical molecular events occurring prior to final T-lineage determination. This study additionally validates a novel, tractable and more rapid approach for the study of LCR activity in T cells, and its translation to therapeutic genetic engineering. PMID:23720809

Phototransfection of mouse embryonic stem cells with plasmid DNA using femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Thobakgale, Lebogang; Manoto, Sello Lebohang; Ombinda Lemboumba, Saturnin; Maaza, Malik; Mthunzi-Kufa, Patience

2017-02-01

Cellular manipulation by delivery of molecules into cells has been applied extensively in tissue engineering research for medical applications . The different molecular delivery techniques used range from viral and chemical agents to physical and electrical methods. Although successful in most studies, these techniques have inherent difficulties such as toxicity, unwanted genetic mutations and low reproducibility respectively. Literature recognizes pulsed lasers at femtosecond level to be most efficient in photonic interactions with biological material. As of late, laser pulses have been used for drug and DNA delivery into cells via transient optical perforation of the cellular membrane. Thus in this study, we design and construct an optical system coupled to a femtosecond laser for the purpose of phototransfection or insertion of plasmid DNA (pDNA) into cells using lasers. We used fluorescent green protein (pGFP) to transfect mouse embryonic stem cells as our model. Secondly, we applied fluorescence imaging to view the extent of DNA delivery using this method. We also assessed the biocompatibility of our system by performing molecular assays of the cells post irradiation using adenosine triphosphate (ATP) and lactate dehydrogenase (LDH).

Imaging of murine embryonic cardiovascular development using optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Huang, Yongyang; Degenhardt, Karl R.; Astrof, Sophie; Zhou, Chao

2016-03-01

We have demonstrated the capability of spectral domain optical coherence tomography (SDOCT) system to image full development of mouse embryonic cardiovascular system. Monitoring morphological changes of mouse embryonic heart occurred in different embryonic stages helps identify structural or functional cardiac anomalies and understand how these anomalies lead to congenital heart diseases (CHD) present at birth. In this study, mouse embryo hearts ranging from E9.5 to E15.5 were prepared and imaged in vitro. A customized spectral domain OCT system was used for imaging, with a central wavelength of 1310nm, spectral bandwidth of ~100nm and imaging speed of 47kHz A-scans/s. Axial resolution of this system was 8.3µm in air, and transverse resolution was 6.2 µm with 5X objective. Key features of mouse embryonic cardiovascular development such as vasculature remodeling into circulatory system, separation of atria and ventricles and emergence of valves could be clearly seen in three-dimensional OCT images. Optical clearing was applied to overcome the penetration limit of OCT system. With high resolution, fast imaging speed, 3D imaging capability, OCT proves to be a promising biomedical imaging modality for developmental biology studies, rivaling histology and micro-CT.

Human amniotic epithelial cell feeder layers maintain mouse embryonic stem cell pluripotency via epigenetic regulation of the c-Myc promoter.

PubMed

Liu, Te; Cheng, Weiwei; Liu, Tianjin; Guo, Lihe; Huang, Qin; Jiang, Lizhen; Du, Xiling; Xu, Fuhui; Liu, Zhixue; Lai, Dongmei

2010-02-01

Mouse embryonic stem cells (ESCs) are typically cultured on a feeder layer of mouse embryonic fibroblasts (MEFs), with leukemia inhibitory factor (LIF) added to maintain them in an undifferentiated state. We have previously shown that human amniotic epithelial cells (hAECs) can be used as feeder cells to maintain mouse ESC pluripotency, but the mechanism for this is unknown. In the present study, we found that CpG islands 5' of the c-Myc gene remain hypomethylated in mouse ESCs cultured on hAECs. In addition, levels of acetylation of histone H3 and trimethylation of histone H3K4 in the c-Myc gene promoter were higher in ES cells cultured on hAECs than those in ES cells cultured on MEFs. These data suggested that hAECs can alter mouse ESC gene expression via epigenetic modification of c-Myc, providing a possible mechanism for the hAEC-induced maintenance of ESCs in an undifferentiated state.

Inactivation of an integrated antibiotic resistance gene in mammalian cells to re-enable antibiotic selection.

PubMed

Ni, Peiling; Zhang, Qian; Chen, Haixia; Chen, Lingyi

2014-01-01

Removing an antibiotic resistance gene allows the same antibiotic to be re-used in the next round of genetic manipulation. Here we applied the CRISPR/Cas system to disrupt the puromycin resistance gene in an engineered mouse embryonic stem cell line and then re-used puromycin selection in the resulting cells to establish stable reporter cell lines. With the CRISPR/Cas system, pre-engineered sequences, such as loxP or FRT, are not required. Thus, this technique can be used to disrupt antibiotic resistance genes that cannot be removed by the Cre-loxP and Flp-FRT systems.

Normal embryonic and germ cell development in mice lacking alpha 1,3-fucosyltransferase IX (Fut9) which show disappearance of stage-specific embryonic antigen 1.

PubMed

Kudo, Takashi; Kaneko, Mika; Iwasaki, Hiroko; Togayachi, Akira; Nishihara, Shoko; Abe, Kuniya; Narimatsu, Hisashi

2004-05-01

Stage-specific embryonic antigen 1 (SSEA-1), an antigenic epitope defined as a Lewis x carbohydrate structure, is expressed during the 8-cell to blastocyst stages in mouse embryos and in primordial germ cells, undifferentiated embryonic stem cells, and embryonic carcinoma cells. For many years, SSEA-1 has been implicated in the development of mouse embryos as a functional carbohydrate epitope in cell-to-cell interaction during morula compaction. In a previous study, alpha 1,3-fucosyltransferase IX (Fut9) exhibited very strong activity for the synthesis of Lewis x compared to other alpha 1,3-fucosyltransferases in an in vitro substrate specificity assay. Fut4 and Fut9 transcripts were expressed in mouse embryos. The Fut9 transcript was detected in embryonic-day-13.5 gonads containing primordial germ cells, but the Fut4 transcript was not. In order to identify the role of SSEA-1 and determine the key enzyme for SSEA-1 synthesis in vivo, we have generated Fut9-deficient (Fut9(-/-)) mice. Fut9(-/-) mice develop normally, with no gross phenotypic abnormalities, and are fertile. Immunohistochemical analysis revealed an absence of SSEA-1 expression in early embryos and primordial germ cells of Fut9(-/-) mice. Therefore, we conclude that expression of the SSEA-1 epitope in the developing mouse embryo is not essential for embryogenesis in vivo.

EMG1 is essential for mouse pre-implantation embryo development.

PubMed

Wu, Xiaoli; Sandhu, Sumit; Patel, Nehal; Triggs-Raine, Barbara; Ding, Hao

2010-09-21

Essential for mitotic growth 1 (EMG1) is a highly conserved nucleolar protein identified in yeast to have a critical function in ribosome biogenesis. A mutation in the human EMG1 homolog causes Bowen-Conradi syndrome (BCS), a developmental disorder characterized by severe growth failure and psychomotor retardation leading to death in early childhood. To begin to understand the role of EMG1 in mammalian development, and how its deficiency could lead to Bowen-Conradi syndrome, we have used mouse as a model. The expression of Emg1 during mouse development was examined and mice carrying a null mutation for Emg1 were generated and characterized. Our studies indicated that Emg1 is broadly expressed during early mouse embryonic development. However, in late embryonic stages and during postnatal development, Emg1 exhibited specific expression patterns. To assess a developmental role for EMG1 in vivo, we exploited a mouse gene-targeting approach. Loss of EMG1 function in mice arrested embryonic development prior to the blastocyst stage. The arrested Emg1-/- embryos exhibited defects in early cell lineage-specification as well as in nucleologenesis. Further, loss of p53, which has been shown to rescue some phenotypes resulting from defects in ribosome biogenesis, failed to rescue the Emg1-/- pre-implantation lethality. Our data demonstrate that Emg1 is highly expressed during mouse embryonic development, and essential for mouse pre-implantation development. The absolute requirement for EMG1 in early embryonic development is consistent with its essential role in yeast. Further, our findings also lend support to the previous study that showed Bowen-Conradi syndrome results from a partial EMG1 deficiency. A complete deficiency would not be expected to be compatible with a live birth.

REDOX DISRUPTING POTENTIAL OF TOXCAST CHEMICALS RANKED BY ACTIVITY IN MOUSE EMBRYONIC STEM CELLS

EPA Science Inventory

To gain insight regarding the adverse outcome pathways leading to developmental toxicity following exposure to chemicals, we evaluated ToxCast™ Phase I chemicals in an adherent mouse embryonic stem cell (mESC) assay and identified a redox sensitive pathway that correlated with al...

Redox Disrupting Potential of ToxCast™Chemicals Ranked by Activity in Mouse Embryonic Stem Cells

EPA Science Inventory

Little is known regarding the adverse outcome pathways responsible for developmental toxicity following exposure to chemicals. An evaluation of Toxoast™ Phase I chemicals in an adherent mouse embryonic stem cell (mESC) assay revealed a redox sensitive pathway that correlated with...

Assessment of a 42 metal salts chemical library in mouse embryonic stem cells

EPA Science Inventory

The developmental effects of xenobiotics on differentiation can be profiled using mouse embryonic stem cells (mESCs). The adherent cell differentiation and cytotoxicity (ACDC) technique was used to evaluate a library of 42 metal and metaloid salts. Jl mESCs were allowed to prolif...

Developing predictions of in vivo developmental toxicity of ToxCast chemicals using mouse embryonic stem cells.

EPA Science Inventory

Developing predictions of in vivo developmental toxicity of ToxCast chemicals using mouse embryonic stem cells S. Hunter, M. Rosen, M. Hoopes, H. Nichols, S. Jeffay, K. Chandler1, Integrated Systems Toxicology Division, National Health and Environmental Effects Research Labor...

Investigation of a redox-sensitive predictive model of mouse embryonic stem cells differentiation using quantitative nuclease protection assays and glutathione redox status

EPA Science Inventory

Investigation of a redox-sensitive predictive model of mouse embryonic stem cell differentiation via quantitative nuclease protection assays and glutathione redox status Chandler KJ,Hansen JM, Knudsen T,and Hunter ES 1. U.S. Environmental Protection Agency, Research Triangl...

CHANGES IN EXPRESSION OF PHOSPHORYLATED AND TOTAL ERK 1/2 IN TCDD-EXPOSED EMBRYONIC MOUSE PALATES

EPA Science Inventory

CHANGES IN EXPRESSION OF PHOSPHORYLATED AND TOTAL ERK1/2 IN TCDD-EXPOSED EMBRYONIC MOUSE PALATES.
C Wolf and B Abbott, USEPA, ORD, NHEERL, Reproductive Toxicology Division, Research Triangle Park, NC 27711

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces cleft palate...

Screening ToxCast™ Phase I Chemicals in a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) Assay

EPA Science Inventory

An Adherent Cell Differentiation and Cytotoxicity (ACDC) in vitro assay with mouse embryonic stem cells was used to screen the ToxCast Phase I chemical library for effects on cellular differentiation and cell number. The U.S. Environmental Protection Agency (EPA) established the ...

In vitro developmental model of the gastrointestinal tract from mouse embryonic stem cells.

PubMed

Torihashi, Shigeko; Kuwahara, Masaki; Kurahashi, Masaaki

2007-10-01

Mouse embryonic stem (ES) cells are pluripotent and retain their potential to form cells, tissues and organs originated from three embryonic germ layers. Recently, we developed in vitro organ--gut-like structures--from mouse ES cells. They had basically similar morphological features to a mouse gastrointestinal tract in vivo composed of three distinct layers (i.e., epithelium, connective tissue and musculature). Gut-like structures showed spontaneous contractions derived from pacemaker cells (interstitial cells of Cajal) in the musculature. We also examined their formation process and expression pattern of transcription factors crucial for gut organogenesis such as Id2, Sox17, HNF3beta/Foxa2 and GATA4. We found that they mimic the development of embryonic gut in vivo and showed a similar expression pattern of common transcription factors. They also maintain their developmental potential after transplantation to a renal capsule. Therefore, gut-like structures are suitable for in vitro models of gastrointestinal tracts and their development. In addition, we pointed out several unique features different from gut in vivo that provide useful and advantageous tools to investigate the developmental mechanism of the gastrointestinal tract.

Live dynamic imaging and analysis of developmental cardiac defects in mouse models with optical coherence tomography

NASA Astrophysics Data System (ADS)

Lopez, Andrew L.; Wang, Shang; Garcia, Monica; Valladolid, Christian; Larin, Kirill V.; Larina, Irina V.

2015-03-01

Understanding mouse embryonic development is an invaluable resource for our interpretation of normal human embryology and congenital defects. Our research focuses on developing methods for live imaging and dynamic characterization of early embryonic development in mouse models of human diseases. Using multidisciplinary methods: optical coherence tomography (OCT), live mouse embryo manipulations and static embryo culture, molecular biology, advanced image processing and computational modeling we aim to understand developmental processes. We have developed an OCT based approach to image live early mouse embryos (E8.5 - E9.5) cultured on an imaging stage and visualize developmental events with a spatial resolution of a few micrometers (less than the size of an individual cell) and a frame rate of up to hundreds of frames per second and reconstruct cardiodynamics in 4D (3D+time). We are now using these methods to study how specific embryonic lethal mutations affect cardiac morphology and function during early development.

Nonpermissiveness for mouse embryonic stem (ES) cell derivation circumvented by a single backcross to 129/Sv strain: establishment of ES cell lines bearing the Omd conditional lethal mutation.

PubMed

Kress, C; Vandormael-Pournin, S; Baldacci, P; Cohen-Tannoudji, M; Babinet, C

1998-12-01

The inbred mouse strain DDK carries a conditional early embryonic lethal mutation that is manifested when DDK females are crossed to males of other inbred strains but not in the corresponding reciprocal crosses. It has been shown that embryonic lethality could be assigned to a single genetic locus called Ovum mutant (Om), on Chromosome (Chr) 11 near Syca 1. In the course of our study of the molecular mechanisms underlying the embryonic lethality, we were interested in deriving an embryonic stem cell bearing the Om mutation in the homozygous state (Omd/Omd). However, it turned out that DDK is nonpermissive for ES cell establishment, with a standard protocol. Here we show that permissiveness could be obtained using Omd/Omd blastocysts with a 75% 129/Sv and 25% DDK genetic background. Several germline-competent Omd/Omd ES cell lines have been derived from blastocysts of this genotype. Such a scenario could be extended to the generation of ES cell lines bearing any mutation present in an otherwise nonpermissive mouse strain.

Fucci2a: a bicistronic cell cycle reporter that allows Cre mediated tissue specific expression in mice.

PubMed

Mort, Richard Lester; Ford, Matthew Jonathan; Sakaue-Sawano, Asako; Lindstrom, Nils Olof; Casadio, Angela; Douglas, Adam Thomas; Keighren, Margaret Anne; Hohenstein, Peter; Miyawaki, Atsushi; Jackson, Ian James

2014-01-01

Markers of cell cycle stage allow estimation of cell cycle dynamics in cell culture and during embryonic development. The Fucci system incorporates genetically encoded probes that highlight G1 and S/G2/M phases of the cell cycle allowing live imaging. However the available mouse models that incorporate Fucci are beset by problems with transgene inactivation, varying expression level, lack of conditional potential and/or the need to maintain separate transgenes-there is no transgenic mouse model that solves all these problems. To address these shortfalls we re-engineered the Fucci system to create 2 bicistronic Fucci variants incorporating both probes fused using the Thosea asigna virus 2A (T2A) self cleaving peptide. We characterize these variants in stable 3T3 cell lines. One of the variants (termed Fucci2a) faithfully recapitulated the nuclear localization and cell cycle stage specific florescence of the original Fucci system. We go on to develop a conditional mouse allele (R26Fucci2aR) carefully designed for high, inducible, ubiquitous expression allowing investigation of cell cycle status in single cell lineages within the developing embryo. We demonstrate the utility of R26Fucci2aR for live imaging by using high resolution confocal microscopy of ex vivo lung, kidney and neural crest development. Using our 3T3 system we describe and validate a method to estimate cell cycle times from relatively short time-lapse sequences that we then apply to our neural crest data. The Fucci2a system and the R26Fucci2aR mouse model are compelling new tools for the investigation of cell cycle dynamics in cell culture and during mouse embryonic development.

Primary Tumor and MEF Cell Isolation to Study Lung Metastasis.

PubMed

Dong, Shengli; Maziveyi, Mazvita; Alahari, Suresh K

2015-05-20

In breast tumorigenesis, the metastatic stage of the disease poses the greatest threat to the affected individual. Normal breast cells with altered genotypes now possess the ability to invade and survive in other tissues. In this protocol, mouse mammary tumors are removed and primary cells are prepared from tumors. The cells isolated from this procedure are then available for gene profiling experiments. For successful metastasis, these cells must be able to intravasate, survive in circulation, extravasate to distant organs, and survive in that new organ system. The lungs are the typical target of breast cancer metastasis. A set of genes have been discovered that mediates the selectivity of metastasis to the lung. Here we describe a method of studying lung metastasis from a genetically engineered mouse model.. Furthermore, another protocol for analyzing mouse embryonic fibroblasts (MEFs) from the mouse embryo is included. MEF cells from the same animal type provide a clue of non-cancer cell gene expression. Together, these techniques are useful in studying mouse mammary tumorigenesis, its associated signaling mechanisms and pathways of the abnormalities in embryos.

Evaluation of an adherent mouse embryonic stem cell in vitro assay to predict developmental toxicity of ToxCast chemicals.

EPA Science Inventory

The potential for most environmental chemicals to produce developmental toxicity is unknown. Mouse embryonic stem cell (mESC) assays are an alternative in vitro model to assess chemicals. The chemical space evaluated using mESC and compared to in vivo is limited. We used an adher...

Defining the molecular pathologies in cloaca malformation: similarities between mouse and human

PubMed Central

Runck, Laura A.; Method, Anna; Bischoff, Andrea; Levitt, Marc; Peña, Alberto; Collins, Margaret H.; Gupta, Anita; Shanmukhappa, Shiva; Wells, James M.; Guasch, Géraldine

2014-01-01

Anorectal malformations are congenital anomalies that form a spectrum of disorders, from the most benign type with excellent functional prognosis, to very complex, such as cloaca malformation in females in which the rectum, vagina and urethra fail to develop separately and instead drain via a single common channel into the perineum. The severity of this phenotype suggests that the defect occurs in the early stages of embryonic development of the organs derived from the cloaca. Owing to the inability to directly investigate human embryonic cloaca development, current research has relied on the use of mouse models of anorectal malformations. However, even studies of mouse embryos lack analysis of the earliest stages of cloaca patterning and morphogenesis. Here we compared human and mouse cloaca development and retrospectively identified that early mis-patterning of the embryonic cloaca might underlie the most severe forms of anorectal malformation in humans. In mouse, we identified that defective sonic hedgehog (Shh) signaling results in early dorsal-ventral epithelial abnormalities prior to the reported defects in septation. This is manifested by the absence of Sox2 and aberrant expression of keratins in the embryonic cloaca of Shh knockout mice. Shh knockout embryos additionally develop a hypervascular stroma, which is defective in BMP signaling. These epithelial and stromal defects persist later, creating an indeterminate epithelium with molecular alterations in the common channel. We then used these animals to perform a broad comparison with patients with mild-to-severe forms of anorectal malformations including cloaca malformation. We found striking parallels with the Shh mouse model, including nearly identical defective molecular identity of the epithelium and surrounding stroma. Our work strongly suggests that early embryonic cloacal epithelial differentiation defects might be the underlying cause of severe forms of anorectal malformations in humans. Moreover, deranged Shh and BMP signaling is correlated with severe anorectal malformations in both mouse and humans. PMID:24524909

Magnetic resonance imaging study of eye congenital birth defects in mouse model

PubMed Central

Tucker, Zachary; Mongan, Maureen; Meng, Qinghang; Xia, Ying

2017-01-01

Purpose Embryonic eyelid closure is a well-documented morphogenetic episode in mammalian eye development. Detection of eyelid closure defect in humans is a major challenge because eyelid closure and reopen occur entirely in utero. As a consequence, congenital eye defects that are associated with failure of embryonic eyelid closure remain unknown. To fill the gap, we developed a mouse model of defective eyelid closure. This preliminary work demonstrates that the magnetic resonance imaging (MRI) approach can be used for the detection of extraocular muscle abnormalities in the mouse model. Methods Mice with either normal (Map3k1+/−) or defective (Map3k1−/−) embryonic eyelid closure were used in this study. Images of the extraocular muscles were obtained with a 9.4 T high resolution microimaging MRI system. The extraocular muscles were identified, segmented, and measured in each imaging slice using an in-house program. Results In agreement with histological findings, the imaging data show that mice with defective embryonic eyelid closure develop less extraocular muscle than normal mice. In addition, the size of the eyeballs was noticeably reduced in mice with defective embryonic eyelid closure. Conclusions We demonstrated that MRI can potentially be used for the study of extraocular muscle in the mouse model of the eye open-at-birth defect, despite the lack of specificity of muscle group provided by the current imaging resolution. PMID:28848319

MicroRNA-130b targets Fmr1 and regulates embryonic neural progenitor cell proliferation and differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, Xi; Zhang, Kunshan; Wang, Yanlu

2013-10-04

Highlights: •We found that the 3′ UTR of the Fmr1 mRNA is a target of miR-130b. •MiR-130b suppresses the expression of Fmr1 in mouse embryonic stem cell. •MiR-130b alters the proliferation of mouse embryonic stem cell. •MiR-130b alters fate specification of mouse embryonic stem cell. -- Abstract: Fragile X syndrome, one of the most common forms of inherited mental retardation, is caused by expansion of the CGG repeat in the 5′-untranslated region of the X-linked Fmr1 gene, which results in transcriptional silencing and loss of expression of its encoded protein FMRP. The loss of FMRP increases proliferation and alters fatemore » specification in adult neural progenitor cells (aNPCs). However, little is known about Fmr1 mRNA regulation at the transcriptional and post-transcriptional levels. In the present study, we report that miR-130b regulated Fmr1 expression by directly targeting its 3′-untranslated region (3′ UTR). Up-regulation of miR-130b in mouse embryonic neural progenitor cells (eNPCs) decreased Fmr1 expression, markedly increased eNPC proliferation and altered the differentiation tendency of eNPCs, suggesting that antagonizing miR-130b may be a new therapeutic entry point for treating Fragile X syndrome.« less

Lamin A/C Haploinsufficiency Modulates the Differentiation Potential of Mouse Embryonic Stem Cells

PubMed Central

Sehgal, Poonam; Chaturvedi, Pankaj; Kumaran, R. Ileng; Kumar, Satish; Parnaik, Veena K.

2013-01-01

Background Lamins are structural proteins that are the major determinants of nuclear architecture and play important roles in various nuclear functions including gene regulation and cell differentiation. Mutations in the human lamin A gene cause a spectrum of genetic diseases that affect specific tissues. Most available mouse models for laminopathies recapitulate disease symptoms for muscle diseases and progerias. However, loss of human lamin A/C also has highly deleterious effects on fetal development. Hence it is important to understand the impact of lamin A/C expression levels on embryonic differentiation pathways. Methodology and Principal Findings We have investigated the differentiation potential of mouse embryonic stem cells containing reduced levels of lamin A/C by detailed lineage analysis of embryoid bodies derived from these cells by in vitro culture. We initially carried out a targeted disruption of one allele of the mouse lamin A/C gene (Lmna). Undifferentiated wild-type and Lmna+/− embryonic stem cells showed similar expression of pluripotency markers and cell cycle profiles. Upon spontaneous differentiation into embryoid bodies, markers for visceral endoderm such as α-fetoprotein were highly upregulated in haploinsufficient cells. However, neuronal markers such as β-III tubulin and nestin were downregulated. Furthermore, we observed a reduction in the commitment of Lmna+/− cells into the myogenic lineage, but no discernible effects on cardiac, adipocyte or osteocyte lineages. In the next series of experiments, we derived embryonic stem cell clones expressing lamin A/C short hairpin RNA and examined their differentiation potential. These cells expressed pluripotency markers and, upon differentiation, the expression of lineage-specific markers was altered as observed with Lmna+/− embryonic stem cells. Conclusions We have observed significant effects on embryonic stem cell differentiation to visceral endoderm, neuronal and myogenic lineages upon depletion of lamin A/C. Hence our results implicate lamin A/C level as an important determinant of lineage-specific differentiation during embryonic development. PMID:23451281

Studies of teratomas in mice: possibilities for the future production of animal models.

PubMed Central

Lehman, J. M.

1980-01-01

The murine teratoma-teratocarcinoma has become an interesting model for the study of neoplastic transformation, developmental biology, and possibly a useful system for genetic studies. These tumors arise spontaneously in 129 strain mice and can be induced in other strains by transplanting early embryos or portions of embryos into extrauterine sites. The majority of these tumors are benign, but some are capable of transplantation due to the presence of the stem cell, embryonal carcinoma, which is a multipotential cell able to proliferate and also differentiate into tissues and cell types representative of all the embryonic germ layers. It has been elegantly shown by transplantation of embryonal carcinoma cells into blastocysts which are then placed into a pseudopregnant mouse that a normal mouse is obtained composed of cells from the host blastocyst and also cells from the malignant embryonal carcinoma. Therefore, under this set of circumstances, embryonal carcinoma cells are induced to functionally differentiate into multiple cell and tissue types which are benign and able to contribute to the development of a mouse. The adaptation of the embryonal carcinoma cell to tissue culture has allowed the manipulation of these cells with subsequent selection of mutant cells which can be further transplanted into blastocysts to obtain a mouse which contains these mutant cells. If the mutant cells have populated the germ line, it may be possible to obtain a stock of mice with the lesion present in all cells. This system may be exploitable for studies in neoplasia, developmental biology, and with proper selection procedures, allow the development of new genetic strains of mice. PMID:7457573

Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: I--Comparative fundamental cryobiology of multiple mouse embryonic stem cell lines and the implications for embryonic stem cell cryopreservation protocols.

PubMed

Kashuba, Corinna M; Benson, James D; Critser, John K

2014-04-01

The post-thaw recovery of mouse embryonic stem cells (mESCs) is often assumed to be adequate with current methods. However as this publication will show, this recovery of viable cells actually varies significantly by genetic background. Therefore there is a need to improve the efficiency and reduce the variability of current mESC cryopreservation methods. To address this need, we employed the principles of fundamental cryobiology to improve the cryopreservation protocol of four mESC lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1 mESCs) through a comparative study characterizing the membrane permeability characteristics and membrane integrity osmotic tolerance limits of each cell line. In the companion paper, these values were used to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures, and then these predicted optimal protocols were validated against standard freezing protocols. Copyright © 2014 Elsevier Inc. All rights reserved.

Worldwide Emerging Environmental Issues Affecting the U.S. Military. Summarizing Environmental Security Monthly Scanning July 2007 - December 2007

DTIC Science & Technology

2007-12-01

times more livelihoods are devastated by natural disasters than by war worldwide, at the moment, and this is going to be much worse, the way the...Act of 2007––that would require cleaner fuels and engines in all ocean- going vessels calling at U.S. ports––was introduced in the Senate (SB 1499) and...to multi-walled carbon nanotubes ( MWCNT ) in mouse embryonic stem cells. The methodology used is highly versatile for testing genotoxicity and hence

Laminin- and basement membrane-polycaprolactone blend nanofibers as a scaffold for regenerative medicine.

PubMed

Neal, Rebekah A; Lenz, Steven M; Wang, Tiffany; Abebayehu, Daniel; Brooks, Benjamin P C; Ogle, Roy C; Botchwey, Edward A

2014-09-01

Mimicking one or more components of the basement membrane (BM) holds great promise for overcoming insufficiencies in tissue engineering therapies. We have electrospun laminin nanofibers (NFs) isolated from the murine Engelbreth-Holm Swarm (EHS) tumor and evaluated them as a scaffold for embryonic stem cell culture. Seeded human embryonic stem cells were found to better maintain their undifferentiated, colony environment when cultured on laminin NFs compared to laminin mats, with 75% remaining undifferentiated on NFs. Mouse embryonic stem cells cultured on 10% laminin-polycaprolactone (PCL) NFs maintained their colony formation for twice as long without passage compared to those on PCL or gelatin substrates. In addition, we have established a protocol for electrospinning reconstituted basement membrane aligned (RBM)-PCL NFs within 10° of angular deviation. Neuron-like PC12 cells show significantly greater attachment (p < 0.001) and percentage of neurite-extending cells in vitro on 10% RBM-PCL NFs when compared to 1% and 0% RBM-PCL NFs (p < 0.015 and p < 0.001, respectively). Together, these results implicate laminin- and RBM-PCL scaffolds as a promising biomimetic substrate for regenerative medicine applications.

Primitive erythrocytes are generated from hemogenic endothelial cells.

PubMed

Stefanska, Monika; Batta, Kiran; Patel, Rahima; Florkowska, Magdalena; Kouskoff, Valerie; Lacaud, Georges

2017-07-25

Primitive erythroblasts are the first blood cells generated during embryonic hematopoiesis. Tracking their emergence both in vivo and in vitro has remained challenging due to the lack of specific cell surface markers. To selectively investigate primitive erythropoiesis, we have engineered a new transgenic embryonic stem (ES) cell line, where eGFP expression is driven by the regulatory sequences of the embryonic βH1 hemoglobin gene expressed specifically in primitive erythroid cells. Using this ES cell line, we observed that the first primitive erythroblasts are detected in vitro around day 1.5 of blast colony differentiation, within the cell population positive for the early hematopoietic progenitor marker CD41. Moreover, we establish that these eGFP + cells emerge from a hemogenic endothelial cell population similarly to their definitive hematopoietic counterparts. We further generated a corresponding βH1-eGFP transgenic mouse model and demonstrated the presence of a primitive erythroid primed hemogenic endothelial cell population in the developing embryo. Taken together, our findings demonstrate that both in vivo and in vitro primitive erythrocytes are generated from hemogenic endothelial cells.

GLUCOCORTICOID RECEPTOR EXPRESSION DURING THE DEVELOPMENT OF THE EMBRYONIC MOUSE SECONDARY PALATE

EPA Science Inventory

Glucocorticoids are important regulators of embryonic growth and development. hese effects are mediated through glucocorticoid receptors (GR) which bind to glucocorticoid response elements upstream of regulated genes. his study examines the expression of GR and GR mRNA in embryon...

Ectopic expression of Cripto-1 in transgenic mouse embryos causes hemorrhages, fatal cardiac defects and embryonic lethality

PubMed Central

Lin, Xiaolin; Zhao, Wentao; Jia, Junshuang; Lin, Taoyan; Xiao, Gaofang; Wang, Shengchun; Lin, Xia; Liu, Yu; Chen, Li; Qin, Yujuan; Li, Jing; Zhang, Tingting; Hao, Weichao; Chen, Bangzhu; Xie, Raoying; Cheng, Yushuang; Xu, Kang; Yao, Kaitai; Huang, Wenhua; Xiao, Dong; Sun, Yan

2016-01-01

Targeted disruption of Cripto-1 in mice caused embryonic lethality at E7.5, whereas we unexpectedly found that ectopic Cripto-1 expression in mouse embryos also led to embryonic lethality, which prompted us to characterize the causes and mechanisms underlying embryonic death due to ectopic Cripto-1 expression. RCLG/EIIa-Cre embryos displayed complex phenotypes between embryonic day 14.5 (E14.5) and E17.5, including fatal hemorrhages (E14.5-E15.5), embryo resorption (E14.5-E17.5), pale body surface (E14.5-E16.5) and no abnormal appearance (E14.5-E16.5). Macroscopic and histological examination revealed that ectopic expression of Cripto-1 transgene in RCLG/EIIa-Cre embryos resulted in lethal cardiac defects, as evidenced by cardiac malformations, myocardial thinning, failed assembly of striated myofibrils and lack of heartbeat. In addition, Cripto-1 transgene activation beginning after E8.5 also caused the aforementioned lethal cardiac defects in mouse embryos. Furthermore, ectopic Cripto-1 expression in embryonic hearts reduced the expression of cardiac transcription factors, which is at least partially responsible for the aforementioned lethal cardiac defects. Our results suggest that hemorrhages and cardiac abnormalities are two important lethal factors in Cripto-1 transgenic mice. Taken together, these findings are the first to demonstrate that sustained Cripto-1 transgene expression after E11.5 causes fatal hemorrhages and lethal cardiac defects, leading to embryonic death at E14.5-17.5. PMID:27687577

Intact calcium signaling in adrenergic-deficient embryonic mouse hearts.

PubMed

Peoples, Jessica N; Taylor, David G; Katchman, Alexander N; Ebert, Steven N

2018-01-22

Mouse embryos that lack the ability to produce the adrenergic hormones, norepinephrine (NE) and epinephrine (EPI), due to disruption of the dopamine beta-hydroxylase (Dbh -/- ) gene inevitably perish from heart failure during mid-gestation. Since adrenergic stimulation is well-known to enhance calcium signaling in developing as well as adult myocardium, and impairments in calcium signaling are typically associated with heart failure, we hypothesized that adrenergic-deficient embryonic hearts would display deficiencies in cardiac calcium signaling relative to adrenergic-competent controls at a developmental stage immediately preceding the onset of heart failure, which first appears beginning or shortly after mouse embryonic day 10.5 (E10.5). To test this hypothesis, we used ratiometric fluorescent calcium imaging techniques to measure cytosolic calcium transients, [Ca 2+ ] i in isolated E10.5 mouse hearts. Our results show that spontaneous [Ca 2+ ] i oscillations were intact and robustly responded to a variety of stimuli including extracellular calcium (5 mM), caffeine (5 mM), and NE (100 nM) in a manner that was indistinguishable from controls. Further, we show similar patterns of distribution (via immunofluorescent histochemical staining) and activity (via patch-clamp recording techniques) for the major voltage-gated plasma membrane calcium channel responsible for the L-type calcium current, I Ca,L , in adrenergic-deficient and control embryonic cardiac cells. These results demonstrate that despite the absence of vital adrenergic hormones that consistently leads to embryonic lethality in vivo, intracellular and extracellular calcium signaling remain essentially intact and functional in embryonic mouse hearts through E10.5. These findings suggest that adrenergic stimulation is not required for the development of intracellular calcium oscillations or extracellular calcium signaling through I Ca,L and that aberrant calcium signaling does not likely contribute to the onset of heart failure in this model. Copyright © 2017. Published by Elsevier Inc.

Mechanical preconditioning enables electrophysiologic coupling of skeletal myoblast cells to myocardium

PubMed Central

Treskes, Philipp; Cowan, Douglas B.; Stamm, Christof; Rubach, Martin; Adelmann, Roland; Wittwer, Thorsten; Wahlers, Thorsten

2015-01-01

Objective The effect of mechanical preconditioning on skeletal myoblasts in engineered tissue constructs was investigated to resolve issues associated with conduction block between skeletal myoblast cells and cardiomyocytes. Methods Murine skeletal myoblasts were used to generate engineered tissue constructs with or without application of mechanical strain. After in vitro myotube formation, engineered tissue constructs were co-cultured for 6 days with viable embryonic heart slices. With the use of sharp electrodes, electrical coupling between engineered tissue constructs and embryonic heart slices was assessed in the presence or absence of pharmacologic agents. Results The isolation and expansion procedure for skeletal myoblasts resulted in high yields of homogeneously desmin-positive (97.1% ± 0.1%) cells. Mechanical strain was exerted on myotubes within engineered tissue constructs during gelation of the matrix, generating preconditioned engineered tissue constructs. Electrical coupling between preconditioned engineered tissue constructs and embryonic heart slices was observed; however, no coupling was apparent when engineered tissue constructs were not subjected to mechanical strain. Coupling of cells from engineered tissue constructs to cells in embryonic heart slices showed slower conduction velocities than myocardial cells with the embryonic heart slices (preconditioned engineered tissue constructs vs embryonic heart slices: 0.04 ± 0.02 ms vs 0.10 ± 0.05 ms, P = .011), lower stimulation frequencies (preconditioned engineered tissue constructs vs maximum embryonic heart slices: 4.82 ± 1.42 Hz vs 10.58 ± 1.56 Hz; P = .0009), and higher sensitivities to the gap junction inhibitor (preconditioned engineered tissue constructs vs embryonic heart slices: 0.22 ± 0.07 mmol/L vs 0.93 ± 0.15 mmol/L; P = .0004). Conclusions We have generated skeletal myoblast–based transplantable grafts that electrically couple to myocardium. PMID:22980065

Bloomsbury report on mouse embryo phenotyping: recommendations from the IMPC workshop on embryonic lethal screening.

PubMed

Adams, David; Baldock, Richard; Bhattacharya, Shoumo; Copp, Andrew J; Dickinson, Mary; Greene, Nicholas D E; Henkelman, Mark; Justice, Monica; Mohun, Timothy; Murray, Stephen A; Pauws, Erwin; Raess, Michael; Rossant, Janet; Weaver, Tom; West, David

2013-05-01

Identifying genes that are important for embryo development is a crucial first step towards understanding their many functions in driving the ordered growth, differentiation and organogenesis of embryos. It can also shed light on the origins of developmental disease and congenital abnormalities. Current international efforts to examine gene function in the mouse provide a unique opportunity to pinpoint genes that are involved in embryogenesis, owing to the emergence of embryonic lethal knockout mutants. Through internationally coordinated efforts, the International Knockout Mouse Consortium (IKMC) has generated a public resource of mouse knockout strains and, in April 2012, the International Mouse Phenotyping Consortium (IMPC), supported by the EU InfraCoMP programme, convened a workshop to discuss developing a phenotyping pipeline for the investigation of embryonic lethal knockout lines. This workshop brought together over 100 scientists, from 13 countries, who are working in the academic and commercial research sectors, including experts and opinion leaders in the fields of embryology, animal imaging, data capture, quality control and annotation, high-throughput mouse production, phenotyping, and reporter gene analysis. This article summarises the outcome of the workshop, including (1) the vital scientific importance of phenotyping embryonic lethal mouse strains for basic and translational research; (2) a common framework to harmonise international efforts within this context; (3) the types of phenotyping that are likely to be most appropriate for systematic use, with a focus on 3D embryo imaging; (4) the importance of centralising data in a standardised form to facilitate data mining; and (5) the development of online tools to allow open access to and dissemination of the phenotyping data.

Adverse Outcome Pathways for Embryonic Vascular Disruption and Alternative Methods to Identify Chemical Vascular Disruptor

EPA Science Inventory

Chemically induced vascular toxicity during embryonic development can result in a wide range of adverse prenatal outcomes. We used information from genetic mouse models linked to phenotypic outcomes and a vascular toxicity knowledge base to construct an embryonic vascular disrupt...

Functional optical coherence tomography for live dynamic analysis of mouse embryonic cardiogenesis

NASA Astrophysics Data System (ADS)

Wang, Shang; Lopez, Andrew L.; Larina, Irina V.

2018-02-01

Blood flow, heart contraction, and tissue stiffness are important regulators of cardiac morphogenesis and function during embryonic development. Defining how these factors are integrated is critically important to advance prevention, diagnostics, and treatment of congenital heart defects. Mammalian embryonic development is taking place deep within the female body, which makes cardiodynamic imaging and analysis during early developmental stages in humans inaccessible. With thousands of mutant lines available and well-established genetic manipulation tools, mouse is a great model to understand how biomechanical factors are integrated with molecular pathways to regulate cardiac function and development. Dynamic imaging and quantitative analysis of the biomechanics of live mouse embryos have become increasingly important, which demands continuous advancements in imaging techniques and live assessment approaches. This has been one of the major drives to keep pushing the frontier of embryonic imaging for better resolution, higher speed, deeper penetration, and more diverse and effective contrasts. Optical coherence tomography (OCT) has played a significant role in addressing such demands, and its features in non-labeling imaging, 3D capability, a large working distance, and various functional derivatives allow OCT to cover a number of specific applications in embryonic imaging. Recently, our group has made several technical improvements in using OCT to probe the biomechanical aspects of live developing mouse embryos at early stages. These include the direct volumetric structural and functional imaging of the cardiodynamics, four-dimensional quantitative Doppler imaging and analysis of the cardiac blood flow, and fourdimensional blood flow separation from the cardiac wall tissue in the beating embryonic heart. Here, we present a short review of these studies together with brief descriptions of the previous work that demonstrate OCT as a valuable and useful imaging tool for the research in developmental cardiology.

Genome engineering in cattle: recent technological advancements.

PubMed

Wang, Zhongde

2015-02-01

Great strides in technological advancements have been made in the past decade in cattle genome engineering. First, the success of cloning cattle by somatic cell nuclear transfer (SCNT) or chromatin transfer (CT) is a significant advancement that has made obsolete the need for using embryonic stem (ES) cells to conduct cell-mediated genome engineering, whereby site-specific genetic modifications can be conducted in bovine somatic cells via DNA homologous recombination (HR) and whereby genetically engineered cattle can subsequently be produced by animal cloning from the genetically modified cells. With this approach, a chosen bovine genomic locus can be precisely modified in somatic cells, such as to knock out (KO) or knock in (KI) a gene via HR, a gene-targeting strategy that had almost exclusively been used in mouse ES cells. Furthermore, by the creative application of embryonic cloning to rejuvenate somatic cells, cattle genome can be sequentially modified in the same line of somatic cells and complex genetic modifications have been achieved in cattle. Very recently, the development of designer nucleases-such as zinc finger nucleases (ZFNs) and transcription activator-like effector nuclease (TALENs), and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-has enabled highly efficient and more facile genome engineering in cattle. Most notably, by employing such designer nucleases, genomes can be engineered at single-nucleotide precision; this process is now often referred to as genome or gene editing. The above achievements are a drastic departure from the traditional methods of creating genetically modified cattle, where foreign DNAs are randomly integrated into the animal genome, most often along with the integrations of bacterial or viral DNAs. Here, I review the most recent technological developments in cattle genome engineering by highlighting some of the major achievements in creating genetically engineered cattle for agricultural and biomedical applications.

Mouse is the new woman? Translational research in reproductive immunology.

PubMed

Clark, David A

2016-11-01

In an outbred mating typical of human reproduction, the embryo and feto-placental unit express paternal antigens to which the mother's immune system can react. However, the embryo and feto-placental unit can engineer the maternal immune defense system towards helpful rather than harmful reactions. Indeed, this begins with the prospective mother's exposure to paternal seminal plasma. In this review, the pregnancy complications of implantation failure (infertility), recurrent spontaneous abortion, pre-eclampsia and intrauterine growth restriction, and premature labor are examined to determine the degree of similarity between events in women and events in lab mouse models. The artificially induced model of endometriosis (which contributes to infertility) is also compared to what occurs in women. One may conclude that the female mouse provides a good analog of the human female. Nevertheless, it is always important to validate mouse data with human studies. The discussion focuses on the intrauterine interface between embryonic and placental tissues and maternal uterine tissues and the dialogue that is referred to as cross-talk. Issues relating to bidirectional transplacental traffic of immune system cells are not discussed as there is very little relevant data.

Evaluation of 309 environmental chemicals using a mouse embryonic stem cell adherent cell differentiation and cytotoxicity assay

EPA Science Inventory

The vast landscape of environmental chemicals has motivated the need for alternative methods to traditional whole-animal bioassays in toxicity testing. Embryonic stem (ES) cells provide an in vitro model of embryonic development and an alternative method for assessing development...

Adverse Outcome Pathway for Embryonic Vascular Disruption and Alternative Methods to Identify Chemical Vascular Disruptors During Development

EPA Science Inventory

Chemically induced vascular toxicity during embryonic development can result in a wide range of adverse prenatal outcomes. We used information from genetic mouse models linked to phenotypic outcomes and a vascular toxicity knowledge base to construct an embryonic vascular disrupt...

Laboratory Aspects of Biological Warfare Agents

DTIC Science & Technology

2016-01-01

Embryonated chicken egg yolk sacs have typically been the method of choice for culture. They are inoculated when the embryos are 5-7 days old. The... chicken or mouse embryo fibroblasts, J774.16 mouse macrophages, L929 murine fibroblasts, HEL (human embryonic lung) or vero cells are more commonly...the family, Poxviridae, is a legacy of the original grouping of viruses associated with diseases that produced poxes in the skin, however, if

Adapting in vitro embryonic stem cell differentiation to the study of locus control regions.

PubMed

Lahiji, Armin; Kučerová-Levisohn, Martina; Holmes, Roxanne; Zúñiga-Pflücker, Juan Carlos; Ortiz, Benjamin D

2014-05-01

Numerous locus control region (LCR) activities have been discovered in gene loci important to immune cell development and function. LCRs are a distinct class of cis-acting gene regulatory elements that appear to contain all the DNA sequence information required to establish an independently and predictably regulated gene expression program at any genomic site in native chromatin of a whole animal. As such, LCR-regulated transgenic reporter systems provide invaluable opportunities to investigate the mechanisms of gene regulatory DNA action during development. Furthermore the qualities of LCR-driven gene expression, including spatiotemporal specificity and "integration site-independence" would be highly desirable to incorporate into vectors used in therapeutic genetic engineering. Thus, advancement in the methods used to investigate LCRs is of considerable basic and translational significance. We study the LCR present in the mouse T cell receptor (TCR)-α gene locus. Until recently, transgenic mice provided the only experimental model capable of supporting the entire spectrum of LCR activities. We have recently reported complete manifestation of TCRα LCR function in T cells derived in vitro from mouse embryonic stem cells (ESC), thus validating a complete cell culture model for the full range of LCR activities seen in transgenic mice. Here we discuss the critical parameters involved in studying LCR-regulated gene expression during in vitro hematopoietic differentiation from ESCs. This advance provides an approach to speed progress in the LCR field, and facilitate the clinical application of its findings, particularly to the genetic engineering of T cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Dynamic 3D culture promotes spontaneous embryonic stem cell differentiation in vitro.

PubMed

Gerlach, Jörg C; Hout, Mariah; Edsbagge, Josefina; Björquist, Petter; Lübberstedt, Marc; Miki, Toshio; Stachelscheid, Harald; Schmelzer, Eva; Schatten, Gerald; Zeilinger, Katrin

2010-02-01

Spontaneous in vitro differentiation of mouse embryonic stem cells (mESC) is promoted by a dynamic, three-dimensional (3D), tissue-density perfusion technique with continuous medium perfusion and exchange in a novel four-compartment, interwoven capillary bioreactor. We compared ectodermal, endodermal, and mesodermal immunoreactive tissue structures formed by mESC at culture day 10 with mouse fetal tissue development at gestational day E9.5. The results show that the bioreactor cultures more closely resemble mouse fetal tissue development at gestational day E9.5 than control mESC cultured in Petri dishes.

Matching mice to malignancy: molecular subgroups and models of medulloblastoma

PubMed Central

Lau, Jasmine; Schmidt, Christin; Markant, Shirley L.; Taylor, Michael D.; Wechsler-Reya, Robert J.

2012-01-01

Introduction Medulloblastoma, the largest group of embryonal brain tumors, has historically been classified into five variants based on histopathology. More recently, epigenetic and transcriptional analyses of primary tumors have sub-classified medulloblastoma into four to six subgroups, most of which are incongruous with histopathological classification. Discussion Improved stratification is required for prognosis and development of targeted treatment strategies, to maximize cure and minimize adverse effects. Several mouse models of medulloblastoma have contributed both to an improved understanding of progression and to developmental therapeutics. In this review, we summarize the classification of human medulloblastoma subtypes based on histopathology and molecular features. We describe existing genetically engineered mouse models, compare these to human disease, and discuss the utility of mouse models for developmental therapeutics. Just as accurate knowledge of the correct molecular subtype of medulloblastoma is critical to the development of targeted therapy in patients, we propose that accurate modeling of each subtype of medulloblastoma in mice will be necessary for preclinical evaluation and optimization of those targeted therapies. PMID:22315164

Direct production of mouse disease models by embryo microinjection of TALENs and oligodeoxynucleotides

PubMed Central

Wefers, Benedikt; Meyer, Melanie; Ortiz, Oskar; Hrabé de Angelis, Martin; Hansen, Jens; Wurst, Wolfgang; Kühn, Ralf

2013-01-01

The study of genetic disease mechanisms relies mostly on targeted mouse mutants that are derived from engineered embryonic stem (ES) cells. Nevertheless, the establishment of mutant ES cells is laborious and time-consuming, restricting the study of the increasing number of human disease mutations discovered by high-throughput genomic analysis. Here, we present an advanced approach for the production of mouse disease models by microinjection of transcription activator-like effector nucleases (TALENs) and synthetic oligodeoxynucleotides into one-cell embryos. Within 2 d of embryo injection, we created and corrected chocolate missense mutations in the small GTPase RAB38; a regulator of intracellular vesicle trafficking and phenotypic model of Hermansky-Pudlak syndrome. Because ES cell cultures and targeting vectors are not required, this technology enables instant germline modifications, making heterozygous mutants available within 18 wk. The key features of direct mutagenesis by TALENs and oligodeoxynucleotides, minimal effort and high speed, catalyze the generation of future in vivo models for the study of human disease mechanisms and interventions. PMID:23426636

The synergistic effect of beta-boswellic acid and Nurr1 overexpression on dopaminergic programming of antioxidant glutathione peroxidase-1-expressing murine embryonic stem cells.

PubMed

Abasi, M; Massumi, M; Riazi, G; Amini, H

2012-10-11

Parkinson's disease (PD) is a neurodegenerative disorder in which the nigro-striatal dopaminergic (DAergic) neurons have been selectively lost. Due to side effects of levodopa, a dopamine precursor drug, recently cell replacement therapy for PD has been considered. Lack of sufficient amounts of, embryos and ethical problems regarding the use of dopamine-rich embryonic neural cells have limited the application of these cells for PD cell therapy. Therefore, many investigators have focused on using the pluripotent stem cells to generate DAergic neurons. This study is aimed first to establish a mouse embryonic stem (mES) cell line that can stably co-express Nurr1 (Nuclear receptor subfamily 4, group A, member 2) transcription factor in order to efficiently generate DAergic neurons, and glutathione peroxidase-1 (GPX-1) to protect the differentiated DAergic-like cells against oxidative stress. In addition to genetic engineering of ES cells, the effect of Beta-boswellic acid (BBA) on DAergic differentiation course of mES cells was sought in the present study. To that end, the feeder-independent CGR8 mouse embryonic stem cells were transduced by Nurr1- and GPX-1-harboring Lentiviruses and the generated Nurr1/GPX-1-expresssing ES clones were characterized and verified. Gene expression analyses demonstrated that BBA treatment and overexpression of Nurr1 has a synergistic effect on derivation of DAergic neurons from Nurr1/GPX-1-expressing ES cells. The differentiated cells could exclusively synthesize and secrete dopamine in response to stimuli. Overexpression of GPX-1 in genetically engineered Nurr1/GPX-1-ES cells increased the viability of these cells during their differentiation into CNS stem cells. In conclusion, the results demonstrated that Nurr1-overexpressing feeder-independent ES cells like the feeder-dependent ES cells, can be efficiently programmed into functional DAergic neurons and additional treatment of cells by BBA can even augment this efficiency. GPX-1 overexpression in Nurr1/GPX-1-ES cells increases the viability of differentiated CNS stem-like cells. The result of this study may have impact on future stem cell therapy of PD. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

The miR-290-295 cluster as multi-faceted players in mouse embryonic stem cells.

PubMed

Yuan, Kai; Ai, Wen-Bing; Wan, Lin-Yan; Tan, Xiao; Wu, Jiang-Feng

2017-01-01

Increasing evidence indicates that embryonic stem cell specific microRNAs (miRNAs) play an essential role in the early development of embryo. Among them, the miR-290-295 cluster is the most highly expressed in the mouse embryonic stem cells and involved in various biological processes. In this paper, we reviewed the research progress of the function of the miR-290-295 cluster in embryonic stem cells. The miR-290-295 cluster is involved in regulating embryonic stem cell pluripotency maintenance, self-renewal, and reprogramming somatic cells to an embryonic stem cell-like state. Moreover, the miR-290-295 cluster has a latent pro-survival function in embryonic stem cells and involved in tumourigenesis and senescence with a great significance. Elucidating the interaction between the miR-290-295 cluster and other modes of gene regulation will provide us new ideas on the biology of pluripotent stem cells. In the near future, the broad prospects of the miRNA cluster will be shown in the stem cell field, such as altering cell identities with high efficiency through the transient introduction of tissue-specific miRNA cluster.

Rotating microgravity-bioreactor cultivation enhances the hepatic differentiation of mouse embryonic stem cells on biodegradable polymer scaffolds.

PubMed

Wang, Yingjie; Zhang, Yunping; Zhang, Shichang; Peng, Guangyong; Liu, Tao; Li, Yangxin; Xiang, Dedong; Wassler, Michael J; Shelat, Harnath S; Geng, Yongjian

2012-11-01

Embryonic stem (ES) cells are pluripotent cells that are capable of differentiating all the somatic cell lineages, including those in the liver tissue. We describe the generation of functional hepatic-like cells from mouse ES (mES) cells using a biodegradable polymer scaffold and a rotating bioreactor that allows simulated microgravity. Cells derived from ES cells cultured in the three-dimensional (3D) culture system with exogenous growth factors and hormones can differentiate into hepatic-like cells with morphologic characteristics of typical mature hepatocytes. Reverse-transcription polymerase chain-reaction testing, Western blot testing, immunostaining, and flow cytometric analysis show that these cells express hepatic-specific genes and proteins during differentiation. Differentiated cells on scaffolds further exhibit morphologic traits and biomarkers characteristic of liver cells, including albumin production, cytochrome P450 activity, and low-density lipoprotein uptake. When these stem cell-bearing scaffolds are transplanted into severe combined immunodeficient mice, the 3D constructs remained viable, undergoing further differentiation and maturation of hepatic-like cells in vivo. In conclusion, the growth and differentiation of ES cells in a biodegradable polymer scaffold and a rotating microgravity bioreactor can yield functional and organizational hepatocytes useful for research involving bioartificial liver and engineered liver tissue.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Xiugong, E-mail: xiugong.gao@fda.hhs.gov; Sprando, Robert L.; Yourick, Jeffrey J.

Developmental toxicity testing has traditionally relied on animal models which are costly, time consuming, and require the sacrifice of large numbers of animals. In addition, there are significant disparities between human beings and animals in their responses to chemicals. Thalidomide is a species-specific developmental toxicant that causes severe limb malformations in humans but not in mice. Here, we used microarrays to study transcriptomic changes induced by thalidomide in an in vitro model based on differentiation of mouse embryonic stem cells (mESCs). C57BL/6 mESCs were allowed to differentiate spontaneously and RNA was collected at 24, 48, and 72 h after exposuremore » to 0.25 mM thalidomide. Global gene expression analysis using microarrays revealed hundreds of differentially expressed genes upon thalidomide exposure that were enriched in gene ontology (GO) terms and canonical pathways associated with embryonic development and differentiation. In addition, many genes were found to be involved in small GTPases-mediated signal transduction, heart development, and inflammatory responses, which coincide with clinical evidences and may represent critical embryotoxicities of thalidomide. These results demonstrate that transcriptomics in combination with mouse embryonic stem cell differentiation is a promising alternative model for developmental toxicity assessment. - Highlights: • Studied genomic changes in mouse embryonic stem cells upon thalidomide exposure • Identified gene expression changes that may represent thalidomide embryotoxicity • The toxicogenomic changes coincide well with known thalidomide clinical outcomes. • The mouse embryonic stem cell model is suitable for developmental toxicity testing. • The model has the potential for high-throughput screening of a multitude of compounds.« less

Effect of micro-vibration culture system on embryo development.

PubMed

Hur, Yong Soo; Park, Jeong Hyun; Ryu, Eun Kyung; Park, Sung Jin; Lee, Jun Ho; Lee, Soo Hee; Yoon, Jung; Yoon, San Hyun; Hur, Chang Young; Lee, Won Don; Lim, Jin Ho

2013-06-01

Micro-vibration culture system was examined to determine the effects on mouse and human embryo development and possible improvement of clinical outcomes in poor responders. The embryonic development rates and cell numbers of blastocysts were compared between a static culture group (n = 178) and a micro-vibration culture group (n = 181) in mice. The embryonic development rates and clinical results were compared between a static culture group (n = 159 cycles) and a micro-vibration culture group (n = 166 cycles) in poor responders. A micro-vibrator was set at a frequency of 42 Hz, 5 s/60 min duration for mouse and human embryo development. The embryonic development rate was significantly improved in the micro-vibration culture group in mice (p < 0.05). The cell numbers of mouse blastocysts were significantly higher in the micro-vibration group than in the static culture group (p < 0.05). In the poor responders, the rate of high grade embryos was not significantly improved in the micro-vibration culture group on day 3. However, the optimal embryonic development rate on day 5 was improved in the micro-vibration group, and the total pregnancy rate and implantation rate were significantly higher in the micro-vibration group than in the static culture group (p < 0.05). Micro-vibration culture methods have a beneficial effect on embryonic development in mouse embryos. In poor responders, the embryo development rate was improved to a limited extent under the micro-vibration culture conditions, but the clinical results were significantly improved.

Generation of human-induced pluripotent stem cells from burn patient-derived skin fibroblasts using a non-integrative method.

PubMed

Fu, Shangfeng; Ding, Jianwu; Liu, Dewu; Huang, Heping; Li, Min; Liu, Yang; Tu, Longxiang; Liu, Deming

2018-01-01

Patient specific induced pluripotent stem cells (iPSCs) have been recognized as a possible source of cells for skin tissue engineering. They have the potential to greatly benefit patients with large areas of burned skin or skin defects. However, the integration virus-based reprogramming method is associated with a high risk of genetic mutation and mouse embryonic fibroblast feeder-cells may be a pollutant. In the present study, human skin fibroblasts (HSFs) were successfully harvested from patients with burns and patient-specific iPSCs were generated using a non-integration method with a feeder-free approach. The octamer-binding transcription factor 4 (OCT4), sex-determining region Y box 2 (SOX2) and NANOG transcription factors were delivered using Sendai virus vectors. iPSCs exhibited representative human embryonic stem cell-like morphology and proliferation characteristics. They also expressed pluripotent markers, including OCT4, NANOG, SOX2, TRA181, stage-specific embryonic antigen 4 and TRA-160, and exhibited a normal karyotype. Teratoma and embryoid body formation revealed that iPSCs were able to differentiate into cells of all three germ layers in vitro and in vivo. The results of the present study demonstrate that HSFs derived from patients with burns, may be reprogrammed into stem cells with pluripotency, which provides a basis for cell‑based skin tissue engineering in the future.

Ethanol Inactivated Mouse Embryonic Fibroblasts Maintain the Self-Renew and Proliferation of Human Embryonic Stem Cells.

PubMed

Huang, Boxian; Ning, Song; Zhuang, Lili; Jiang, Chunyan; Cui, Yugui; Fan, Guoping; Qin, Lianju; Liu, Jiayin

2015-01-01

Conventionally, mouse embryonic fibroblasts (MEFs) inactivated by mitomycin C or irradiation were applied to support the self-renew and proliferation of human embryonic stem cells (hESCs). To avoid the disadvangtages of mitomycin C and irradiation, here MEFs were treated by ethanol (ET). Our data showed that 10% ET-inactivated MEFs (eiMEFs) could well maintain the self-renew and proliferation of hESCs. hESCs grown on eiMEFs expressed stem cell markers of NANOG, octamer-binding protein 4 (OCT4), stage-specific embryonic antigen-4 (SSEA4) and tumour related antigen-1-81 (TRA-1-81), meanwhile maintained normal karyotype after long time culture. Also, hESCs cocultured with eiMEFs were able to form embryoid body (EB) in vitro and develop teratoma in vivo. Moreover, eiMEFs could keep their nutrient functions after long time cryopreservation. Our results indicate that the application of eiMEF in hESCs culture is safe, economical and convenient, thus is a better choice.

Subregional localization and characterization of Ly6aGFP-expressing hematopoietic cells in the mouse embryonic head.

PubMed

Li, Zhuan; Vink, Chris S; Mariani, Samanta A; Dzierzak, Elaine

2016-08-01

Hematopoietic cell generation in the midgestation mouse embryo occurs through the natural transdifferentiation of temporally and spatially restricted set of hemogenic endothelial cells. These cells take on hematopoietic fate in the aorta, vitelline and umbilical arteries and appear as hematopoietic cell clusters that emerge from the vascular wall. Genetic and live imaging data have supported this. Recently, the embryonic head has been shown to contain fully functional hematopoietic stem cells (HSC). By lineage tracing, cerebrovascular specific endothelial cells were shown to contribute to the postnatal mouse hematopoietic system. Since Ly6aGFP is a marker of all HSCs, some hematopoietic cluster cells and hemogenic endothelial cells in the midgestation mouse aorta, we examine here whether embryonic head HSCs and vascular endothelial cells are positive for this marker. Whereas some head vasculature, single hematopoietic cells and all HSCs are Ly6aGFP expressing, we do not find clusters of hematopoietic cells emerging from the cerebrovasculature that are characteristic of endothelial-to-hematopoietic transition. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Temporal distribution of endogenous retinoids in the embryonic mouse mandible.

PubMed

Beeman, C S; Kronmiller, J E

1994-09-01

Retinoids play an important part in embryonic pattern formation. They are necessary for normal differentiation of odontogenic tissues and, in excess, disrupt the pattern of tooth formation. Excess retinoids produce supernumerary buds of the dental lamina in the diastema region of the mouse embryonic mandible where teeth do not normally form. This effect is coincident with an increase in epithelial proliferation and an alteration in epidermal growth factor mRNA expression (a gene product necessary for tooth formation). It was found by high-performance liquid chromatography that endogenous retinoids are present in the developing murine mandible and that concentrations of some retinoids reach a peak at the time of the initiation of odontogenesis (dental lamina formation).

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

A new Postdoctoral Fellow position is immediately available in the laboratory of Dr. Terry Yamaguchi at the National Cancer Institute. Dr.Yamaguchi's lab investigates how secreted growth factors regulate the gene regulatory networks that control the fate of embryonic and adult stem cells. Current projects focus on understanding how Wnts and Fgfs regulate the formation and differentiation of the neuromesodermal progenitor (NMP), a multipotent embryonic cell that generates the spinal cord neurons and musculoskeletal system of the body. Using a combination of mouse genetics, mouse and human embryonic stem cell in vitro differentiation, and genomic, proteomic and biochemical approaches, Dr. Yamaguchi’s lab is investigating the molecular mechanisms underlying the activity of key transcriptional determinants of NMP development.

A dual-modality optical coherence tomography and selective plane illumination microscopy system for mouse embryonic imaging

NASA Astrophysics Data System (ADS)

Wu, Chen; Ran, Shihao; Le, Henry; Singh, Manmohan; Larina, Irina V.; Mayerich, David; Dickinson, Mary E.; Larin, Kirill V.

2017-02-01

Both optical coherence tomography (OCT) and selective plane illumination microscopy (SPIM) are frequently used in mouse embryonic research for high-resolution three-dimensional imaging. However, each of these imaging methods provide a unique and independent advantage: SPIM provides morpho-functional information through immunofluorescence and OCT provides a method for whole-embryo 3D imaging. In this study, we have combined rotational imaging OCT and SPIM into a single, dual-modality device to image E9.5 mouse embryos. The results demonstrate that the dual-modality setup is able to provide both anatomical and functional information simultaneously for more comprehensive tissue characterization.

A New Wnt1-CRE TomatoRosa Embryonic Stem Cell Line: A Tool for Studying Neural Crest Cell Integration Capacity.

PubMed

Acuna-Mendoza, Soledad; Martin, Sabrina; Kuchler-Bopp, Sabine; Ribes, Sandy; Thalgott, Jérémy; Chaussain, Catherine; Creuzet, Sophie; Lesot, Hervé; Lebrin, Franck; Poliard, Anne

2017-12-01

Neural crest (NC) cells are a migratory, multipotent population giving rise to numerous lineages in the embryo. Their plasticity renders attractive their use in tissue engineering-based therapies, but further knowledge on their in vivo behavior is required before clinical transfer may be envisioned. We here describe the isolation and characterization of a new mouse embryonic stem (ES) line derived from Wnt1-CRE-R26 Rosa TomatoTdv blastocyst and show that it displays the characteristics of typical ES cells. Further, these cells can be efficiently directed toward an NC stem cell-like phenotype as attested by concomitant expression of NC marker genes and Tomato fluorescence. As native NC progenitors, they are capable of differentiating toward typical derivative phenotypes and interacting with embryonic tissues to participate in the formation of neo-structures. Their specific fluorescence allows purification and tracking in vivo. This cellular tool should facilitate a better understanding of the mechanisms driving NC fate specification and help identify the key interactions developed within a tissue after in vivo implantation. Altogether, this novel model may provide important knowledge to optimize NC stem cell graft conditions, which are required for efficient tissue repair.

Injurious Effects of Emodin on Maturation of Mouse Oocytes, Fertilization and Fetal Development via Apoptosis

PubMed Central

Chang, Mei-Hui; Chang, Shao-Chung; Chan, Wen-Hsiung

2012-01-01

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a major constituent of rhubarb, has a wide range of therapeutic applications. Previous studies have established that emodin induces apoptosis in the inner cell mass and trophectoderm of mouse blastocysts and leads to decreased embryonic development and viability, indicating a role as an injury risk factor for normal embryonic development. However, the mechanisms underlying its hazardous effects have yet to be characterized. In the current study, we further investigated the effects of emodin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, emodin induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with emodin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments using an in vivo mouse model disclosed that consumption of drinking water containing 20–40 μM emodin led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Notably, pretreatment with a caspase-3-specific inhibitor effectively prevented emodin-triggered injury effects, suggesting that impairment of embryo development occurs via a caspase-dependent apoptotic process. PMID:23203041

Localization of trefoil factor family peptide 3 (TFF3) in epithelial tissues originating from the three germ layers of developing mouse embryo.

PubMed

Bijelić, Nikola; Belovari, Tatjana; Tolušić Levak, Maja; Baus Lončar, Mirela

2017-08-20

Trefoil factor family (TFF) peptides are involved in the maintenance of epithelial integrity and epithelial restitution. Mature epithelial tissues originate from different embryonic germ layers. The objective of this research was to explore the presence and localization of TFF3 peptide in mouse embryonic epithelia and to examine if the occurrence of TFF3 peptide is germ layer-dependent. Mouse embryos (14-18 days old) were fixed in 4% paraformaldehyde and embedded in paraffin. Immunohistochemistry was performed with affinity purified rabbit anti-TFF3 antibody, goat anti-rabbit biotinylated secondary antibody and streptavidin-horseradish peroxidase, followed by 3,3'-diaminobenzidine. TFF3 peptide was present in the gastric and intestinal mucosa, respiratory mucosa in the upper and lower airways, pancreas, kidney tubules, epidermis, and oral cavity. The presence and localization of TFF3 peptide was associated with the embryonic stage and tissue differentiation. TFF3 peptide distribution specific to the germ layers was not observed. The role of TFF3 peptide in cell migration and differentiation, immune response, and apoptosis might be associated with specific embryonic epithelial cells. TFF3 peptide may also be considered as a marker for mucosal maturation.

Injurious effects of emodin on maturation of mouse oocytes, fertilization and fetal development via apoptosis.

PubMed

Chang, Mei-Hui; Chang, Shao-Chung; Chan, Wen-Hsiung

2012-10-29

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a major constituent of rhubarb, has a wide range of therapeutic applications. Previous studies have established that emodin induces apoptosis in the inner cell mass and trophectoderm of mouse blastocysts and leads to decreased embryonic development and viability, indicating a role as an injury risk factor for normal embryonic development. However, the mechanisms underlying its hazardous effects have yet to be characterized. In the current study, we further investigated the effects of emodin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, emodin induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with emodin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments using an in vivo mouse model disclosed that consumption of drinking water containing 20-40 μM emodin led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Notably, pretreatment with a caspase-3-specific inhibitor effectively prevented emodin-triggered injury effects, suggesting that impairment of embryo development occurs via a caspase-dependent apoptotic process.

MiRNA-mediated regulation of cell signaling and homeostasis in the early mouse embryo.

PubMed

Pernaute, Barbara; Spruce, Thomas; Rodriguez, Tristan A; Manzanares, Miguel

2011-02-15

At the time of implantation the mouse embryo is composed of three tissues the epiblast, trophectoderm and primitive endoderm. As development progresses the epiblast goes on to form the foetus whilst the trophectoderm and primitive endoderm give rise to extra-embryonic structures with important roles in embryo patterning and nutrition. Dramatic changes in gene expression occur during early embryo development and these require regulation at different levels. miRNAs are small non coding RNAs that have emerged over the last decade as important post-transcriptional repressors of gene expression. The roles played by miRNAs during early mammalian development are only starting to be elucidated. In order to gain insight into the function of miRNAs in the different lineages of the early mouse embryo we have analysed in depth the phenotype of embryos and extra-embryonic stem cells mutant for the miRNA maturation protein Dicer. This study revealed that miRNAs are involved in regulating cell signaling and homeostasis in the early embryo. Specifically, we identified a role for miRNAs in regulating the Erk signaling pathway in the extra-embryonic endoderm, cell cycle progression in extra-embryonic tissues and apoptosis in the epiblast.

Embryonic Lethality of Mitochondrial Pyruvate Carrier 1 Deficient Mouse Can Be Rescued by a Ketogenic Diet

PubMed Central

Krznar, Petra; Hörl, Manuel; Ammar, Zeinab; Montessuit, Sylvie; Pierredon, Sandra; Zamboni, Nicola; Martinou, Jean-Claude

2016-01-01

Mitochondrial import of pyruvate by the mitochondrial pyruvate carrier (MPC) is a central step which links cytosolic and mitochondrial intermediary metabolism. To investigate the role of the MPC in mammalian physiology and development, we generated a mouse strain with complete loss of MPC1 expression. This resulted in embryonic lethality at around E13.5. Mouse embryonic fibroblasts (MEFs) derived from mutant mice displayed defective pyruvate-driven respiration as well as perturbed metabolic profiles, and both defects could be restored by reexpression of MPC1. Labeling experiments using 13C-labeled glucose and glutamine demonstrated that MPC deficiency causes increased glutaminolysis and reduced contribution of glucose-derived pyruvate to the TCA cycle. Morphological defects were observed in mutant embryonic brains, together with major alterations of their metabolome including lactic acidosis, diminished TCA cycle intermediates, energy deficit and a perturbed balance of neurotransmitters. Strikingly, these changes were reversed when the pregnant dams were fed a ketogenic diet, which provides acetyl-CoA directly to the TCA cycle and bypasses the need for a functional MPC. This allowed the normal gestation and development of MPC deficient pups, even though they all died within a few minutes post-delivery. This study establishes the MPC as a key player in regulating the metabolic state necessary for embryonic development, neurotransmitter balance and post-natal survival. PMID:27176894

Nuclei pulposi formation from the embryonic notochord occurs normally in GDF-5-deficient mice.

PubMed

Maier, Jennifer A; Harfe, Brian D

2011-11-15

The transition of the mouse embryonic notochord into nuclei pulposi was determined ("fate mapped") in vivo in growth and differentiating factor-5 (GDF-5)-null mice using the Shhcre and R26R alleles. To determine whether abnormal nuclei pulposi formation from the embryonic notochord was responsible for defects present in adult nuclei pulposi of Gdf-5-null mice. The development, maintenance, and degeneration of the intervertebral disc are not understood. Previously, we demonstrated that all cells in the adult nucleus pulposus of normal mice are derived from the embryonic notochord. Gdf-5-null mice have been reported to contain intervertebral discs in which the nucleus pulposus is abnormal. It is currently unclear if disc defects in Gdf-5-null mice arise during the formation of nuclei pulposi from the notochord during embryogenesis or result from progressive postnatal degeneration of nuclei pulposi. Gdf-5 messenger RNA expression was examined in the discs of wild-type embryos by RNA in situ hybridization to determine when and where this gene was expressed. To examine nucleus pulposus formation in Gdf-5-null mice, intervertebral discs in which embryonic notochord cells were marked were analyzed in newborn and 24-week-old mice. Our Gdf-5 messenger RNA in situ experiments determined that this gene is localized to the annulus fibrosus and not the nucleus pulposus in mouse embryos. Notochord fate-mapping experiments revealed that notochord cells in Gdf-5-null mice correctly form nuclei pulposi. Our data suggest that the defects reported in the nucleus pulposus of adult Gdf-5-null mice do not result from abnormal patterning of the embryonic notochord. The use of mouse alleles to mark cells that produce all cell types that reside in the adult nucleus pulposus will allow for a detailed examination of disc formation in other mouse mutants that have been reported to contain disc defects.

Effect of recombinant-LH and hCG in the absence of FSH on in vitro maturation (IVM) fertilization and early embryonic development of mouse germinal vesicle (GV)-stage oocytes.

PubMed

Dinopoulou, Vasiliki; Drakakis, Peter; Kefala, Stella; Kiapekou, Erasmia; Bletsa, Ritsa; Anagnostou, Elli; Kallianidis, Konstantinos; Loutradis, Dimitrios

2016-06-01

During in vitro maturation (IVM), intrinsic and extrinsic factors must co-operate properly in order to ensure cytoplasmic and nuclear maturation. We examined the possible effect of LH/hCG in the process of oocyte maturation in mice with the addition of recombinant LH (r-LH) and hCG in our IVM cultures of mouse germinal vesicle (GV)-stage oocytes. Moreover, the effects of these hormones on fertilization, early embryonic development and the expression of LH/hCG receptor were examined. Nuclear maturation of GV-stage oocytes was evaluated after culture in the presence of r-LH or hCG. Fertilization rates and embryonic development were assessed after 24h. Total RNA was isolated from oocytes of different stages of maturation and from zygotes and embryos of different stages of development in order to examine the expression of LH/hCG receptor, using RT-PCR. The in vitro nuclear maturation rate of GV-stage oocytes that received hCG was significantly higher compared to the control group. Early embryonic development was increased in the hCG and LH cultures of GV oocytes when LH was further added. The LH/hCG receptor was expressed in all stages of in vitro matured mouse oocytes and in every stage of early embryonic development. Addition of hCG in IVM cultures of mouse GV oocytes increased maturation rates significantly. LH, however, was more beneficial to early embryonic development than hCG. This suggests a promising new technique in basic science research or in clinical reproductive medicine. Copyright © 2016 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Nuclei pulposi formation from the embryonic notochord occurs normally in GDF5-deficient mice

PubMed Central

Maier, Jennifer A.; Harfe, Brian D.

2011-01-01

Study Design The transition of the mouse embryonic notochord into nuclei pulposi was determined (“fate mapped”) in vivo in GDF-5 null mice using the Shhcre and R26R alleles. Objective To determine if abnormal nuclei pulposi formation from the embryonic notochord was responsible for defects present in adult nuclei pulposi of Gdf-5 null mice. Summary of Background Data The development, maintenance, and degeneration of the intervertebral disc are not understood. Previously, we demonstrated that all cells in the adult nucleus pulposus of normal mice are derived from the embryonic notochord. Gdf-5 null mice have been reported to contain intervertebral discs in which the nucleus pulposus is abnormal. It is currently unclear if disc defects in Gdf-5 null mice arise during the formation of nuclei pulposi from the notochord during embryogenesis or resulted from progressive postnatal degeneration of nuclei pulposi. Methods Gdf-5 mRNA expression was examined in the discs of wild-type embryos by RNA in situ hybridization to determine when and where this gene was expressed. To examine nucleus pulposus formation in Gdf-5 null mice, intervertebral discs in which embryonic notochord cells were marked were analyzed in newborn and 24 week old mice. Results Our Gdf-5 mRNA in situ experiments determined that this gene is localized to the annulus fibrosus and not the nucleus pulposus in mouse embryos. Notochord fate mapping experiments revealed that notochord cells in Gdf-5 null mice correctly form nuclei pulposi. Conclusion Our data suggest that the defects reported in the nucleus pulposus of adult Gdf-5 null mice do not result from abnormal patterning of the embryonic notochord. The use of mouse alleles to mark cells that produce all cell types that reside in the adult nucleus pulposus will allow for a detailed examination of disc formation in other mouse mutants that have been reported to contain disc defects. PMID:21278629

A genetic and developmental pathway from STAT3 to the OCT4–NANOG circuit is essential for maintenance of ICM lineages in vivo

PubMed Central

Do, Dang Vinh; Ueda, Jun; Messerschmidt, Daniel M.; Lorthongpanich, Chanchao; Zhou, Yi; Feng, Bo; Guo, Guoji; Lin, Peiyu J.; Hossain, Md Zakir; Zhang, Wenjun; Moh, Akira; Wu, Qiang; Robson, Paul; Ng, Huck Hui; Poellinger, Lorenz; Knowles, Barbara B.; Solter, Davor; Fu, Xin-Yuan

2013-01-01

Although it is known that OCT4–NANOG are required for maintenance of pluripotent cells in vitro, the upstream signals that regulate this circuit during early development in vivo have not been identified. Here we demonstrate, for the first time, signal transducers and activators of transcription 3 (STAT3)-dependent regulation of the OCT4–NANOG circuitry necessary to maintain the pluripotent inner cell mass (ICM), the source of in vitro-derived embryonic stem cells (ESCs). We show that STAT3 is highly expressed in mouse oocytes and becomes phosphorylated and translocates to the nucleus in the four-cell and later stage embryos. Using leukemia inhibitory factor (Lif)-null embryos, we found that STAT3 phosphorylation is dependent on LIF in four-cell stage embryos. In blastocysts, interleukin 6 (IL-6) acts in an autocrine fashion to ensure STAT3 phosphorylation, mediated by janus kinase 1 (JAK1), a LIF- and IL-6-dependent kinase. Using genetically engineered mouse strains to eliminate Stat3 in oocytes and embryos, we firmly establish that STAT3 is essential for maintenance of ICM lineages but not for ICM and trophectoderm formation. Indeed, STAT3 directly binds to the Oct4 and Nanog distal enhancers, modulating their expression to maintain pluripotency of mouse embryonic and induced pluripotent stem cells. These results provide a novel genetic model of cell fate determination operating through STAT3 in the preimplantation embryo and pluripotent stem cells in vivo. PMID:23788624

4D atlas of the mouse embryo for precise morphological staging.

PubMed

Wong, Michael D; van Eede, Matthijs C; Spring, Shoshana; Jevtic, Stefan; Boughner, Julia C; Lerch, Jason P; Henkelman, R Mark

2015-10-15

After more than a century of research, the mouse remains the gold-standard model system, for it recapitulates human development and disease and is quickly and highly tractable to genetic manipulations. Fundamental to the power and success of using a mouse model is the ability to stage embryonic mouse development accurately. Past staging systems were limited by the technologies of the day, such that only surface features, visible with a light microscope, could be recognized and used to define stages. With the advent of high-throughput 3D imaging tools that capture embryo morphology in microscopic detail, we now present the first 4D atlas staging system for mouse embryonic development using optical projection tomography and image registration methods. By tracking 3D trajectories of every anatomical point in the mouse embryo from E11.5 to E14.0, we established the first 4D atlas compiled from ex vivo 3D mouse embryo reference images. The resulting 4D atlas comprises 51 interpolated 3D images in this gestational range, resulting in a temporal resolution of 72 min. From this 4D atlas, any mouse embryo image can be subsequently compared and staged at the global, voxel and/or structural level. Assigning an embryonic stage to each point in anatomy allows for unprecedented quantitative analysis of developmental asynchrony among different anatomical structures in the same mouse embryo. This comprehensive developmental data set offers developmental biologists a new, powerful staging system that can identify and compare differences in developmental timing in wild-type embryos and shows promise for localizing deviations in mutant development. © 2015. Published by The Company of Biologists Ltd.

Formation of Stomach Tissue by Organoid Culture Using Mouse Embryonic Stem Cells.

PubMed

Noguchi, Taka-Aki K; Kurisaki, Akira

2017-01-01

In this chapter, we describe a method for the induction of stomach organoids from mouse embryonic stem (ES) cells. We used an embryoid body-based differentiation method to induce gastric primordial epithelium covered with mesenchyme and further differentiate it in Matrigel by 3D culture. The differentiated organoid contains both corpus- and antrum-specific mature gastric tissue cells. This protocol may be useful for a variety of studies in developmental biology and disease modeling of the stomach.

Toxicity of silver nanoparticles in mouse embryonic stem cells and chemical based reprogramming of somatic cells to sphere cells

NASA Astrophysics Data System (ADS)

Rajanahalli Krishnamurthy, Pavan

Abstract 1: Silver nanoparticles (Ag Np's) have an interesting surface chemistry and unique plasmonic properties. They are used in a wide variety of applications ranging from consumer products like socks, medical dressing, computer chips and it is also shown to have antimicrobial, anti bacterial activity and wound healing. Ag Np toxicity studies have been limited to date which needs to be critically addressed due to its wide applications. Mouse embryonic stem (MES) cells represent a unique cell population with the ability to undergo both self renewal and differentiation. They exhibit very stringent and tightly regulated mechanisms to circumvent DNA damage and stress response. We used 10 nm coated (polysaccharide) and uncoated Ag Np's to test its toxic effects on MES cells. MES cells and embryoid bodies (EB's) were treated with two concentrations of Ag Np's: 5 microg/ml and 50 ug/ml and exposed for 24, 48 and 72 hours. Increased cell death, ROS production and loss of mitochondrial membrane potential and alkaline phosphatase (AP) occur in a time and a concentration dependant manner. Due to increased cell death, there is a progressive increase in Annexin V (apoptosis) and Propidium Iodide (PI) staining (necrosis). Oct4 and Nanog undergo ubiquitination and dephosphorylation post-translational modifications in MES cells thereby altering gene expression of pluripotency factors and differentiation of EB's into all the three embryonic germ layers with specific growth factors were also inhibited after Ag Np exposure. Flow cytometry analysis revealed Ag Np's treated cells had altered cell cycle phases correlating with altered self renewal capacity. Our results suggest that Ag Np's effect MES cell self renewal, pluripotency and differentiation and serves as a perfect model system for studying toxicity induced by engineered Ag Np's. Abstract 2: The reprogramming of fibroblasts to pluripotent stem cells and the direct conversion of fibroblasts to functional neurons has been successfully manipulated by ectopic expression of defined factors. We demonstrate that mouse fibroblasts can be converted into sphere cells by detaching fibroblast cells by proteases and then using AlbuMAX I-containing culture medium without genetic alteration. AlbuMAX I is a lipid-rich albumin. Albumin-associated lipids arachidonic acid (AA) and pluronic F-68 were responsible for this effect. The converted colonies were positive for both alkaline phosphatase and stage specific embryonic antigen-1 (SSEA-1) staining. Global gene expression analysis indicated that the sphere cells were in an intermediate state compared with MES cells and MEF cells. The sphere cells were able to differentiate into tissues representing all three embryonic germ layers following retinoic acid treatment, and also differentiated into smooth muscle cells following treatment with vascular endothelial growth factor (VEGF). The study presented a potential novel approach to transdifferentiate mouse fibroblast cells into other cell lineages mediated by AlbuMAX I-containing culture medium.

Embryonic Stem Cells Contribute to Mouse Chimeras in the Absence of Detectable Cell Fusion

PubMed Central

Kidder, Benjamin L.; Oseth, Leann; Miller, Shanna; Hirsch, Betsy; Verfaillie, Catherine

2008-01-01

Abstract Embryonic stem (ES) cells are capable of differentiating into all embryonic and adult cell types following mouse chimera production. Although injection of diploid ES cells into tetraploid blastocysts suggests that tetraploid cells have a selective disadvantage in the developing embryo, tetraploid hybrid cells, formed by cell fusion between ES cells and somatic cells, have been reported to contribute to mouse chimeras. In addition, other examples of apparent stem cell plasticity have recently been shown to be the result of cell fusion. Here we investigate whether ES cells contribute to mouse chimeras through a cell fusion mechanism. Fluorescence in situ hybridization (FISH) analysis for X and Y chromosomes was performed on dissociated tissues from embryonic, neonatal, and adult wild-type, and chimeric mice to follow the ploidy distributions of cells from various tissues. FISH analysis showed that the ploidy distributions in dissociated tissues, notably the tetraploid cell number, did not differ between chimeric and wild-type tissues. To address the possibility that early cell fusion events are hidden by subsequent reductive divisions or other changes in cell ploidy, we injected Z/EG (lacZ/EGFP) ES cells into ACTB-cre blastocysts. Recombination can only occur as the result of cell fusion, and the recombined allele should persist through any subsequent changes in cell ploidy. We did not detect evidence of fusion in embryonic chimeras either by direct fluorescence microscopy for GFP or by PCR amplification of the recombined Z/EG locus on genomic DNA from ACTB-cre::Z/EG chimeric embryos. Our results argue strongly against cell fusion as a mechanism by which ES cells contribute to chimeras. PMID:18338954

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

The Genetics of Cancer Susceptibility Section in the Mouse Cancer Genetics Program at NCI is seeking a highly motivated postdoctoral researcher to identify novel genetic interactors of BRCA2 using CRISPR-based genetic screen in mouse embryonic stem cells and perform functional studies in mouse models.

Rigid microenvironments promote cardiac differentiation of mouse and human embryonic stem cells

NASA Astrophysics Data System (ADS)

Arshi, Armin; Nakashima, Yasuhiro; Nakano, Haruko; Eaimkhong, Sarayoot; Evseenko, Denis; Reed, Jason; Stieg, Adam Z.; Gimzewski, James K.; Nakano, Atsushi

2013-04-01

While adult heart muscle is the least regenerative of tissues, embryonic cardiomyocytes are proliferative, with embryonic stem (ES) cells providing an endless reservoir. In addition to secreted factors and cell-cell interactions, the extracellular microenvironment has been shown to play an important role in stem cell lineage specification, and understanding how scaffold elasticity influences cardiac differentiation is crucial to cardiac tissue engineering. Though previous studies have analyzed the role of matrix elasticity on the function of differentiated cardiomyocytes, whether it affects the induction of cardiomyocytes from pluripotent stem cells is poorly understood. Here, we examine the role of matrix rigidity on cardiac differentiation using mouse and human ES cells. Culture on polydimethylsiloxane (PDMS) substrates of varied monomer-to-crosslinker ratios revealed that rigid extracellular matrices promote a higher yield of de novo cardiomyocytes from undifferentiated ES cells. Using a genetically modified ES system that allows us to purify differentiated cardiomyocytes by drug selection, we demonstrate that rigid environments induce higher cardiac troponin T expression, beating rate of foci, and expression ratio of adult α- to fetal β- myosin heavy chain in a purified cardiac population. M-mode and mechanical interferometry image analyses demonstrate that these ES-derived cardiomyocytes display functional maturity and synchronization of beating when co-cultured with neonatal cardiomyocytes harvested from a developing embryo. Together, these data identify matrix stiffness as an independent factor that instructs not only the maturation of already differentiated cardiomyocytes but also the induction and proliferation of cardiomyocytes from undifferentiated progenitors. Manipulation of the stiffness will help direct the production of functional cardiomyocytes en masse from stem cells for regenerative medicine purposes.

Periodic harvesting of embryonic stem cells from a hollow-fiber membrane based four-compartment bioreactor.

PubMed

Knöspel, Fanny; Freyer, Nora; Stecklum, Maria; Gerlach, Jörg C; Zeilinger, Katrin

2016-01-01

Different types of stem cells have been investigated for applications in drug screening and toxicity testing. In order to provide sufficient numbers of cells for such in vitro applications a scale-up of stem cell culture is necessary. Bioreactors for dynamic three-dimensional (3D) culture of growing cells offer the option for culturing large amounts of stem cells at high densities in a closed system. We describe a method for periodic harvesting of pluripotent stem cells (PSC) during expansion in a perfused 3D hollow-fiber membrane bioreactor, using mouse embryonic stem cells (mESC) as a model cell line. A number of 100 × 10(6) mESC were seeded in bioreactors in the presence of mouse embryonic fibroblasts (MEF) as feeder cells. Over a cultivation interval of nine days cells were harvested by trypsin perfusion and mechanical agitation every second to third culture day. A mean of 380 × 10(6) mESC could be removed with every harvest. Subsequent to harvesting, cells continued growing in the bioreactor, as determined by increasing glucose consumption and lactate production. Immunocytochemical staining and mRNA expression analysis of markers for pluripotency and the three germ layers showed a similar expression of most markers in the harvested cells and in mESC control cultures. In conclusion, successful expansion and harvesting of viable mESC from bioreactor cultures with preservation of sterility was shown. The present study is the first one showing the feasibility of periodic harvesting of adherent cells from a continuously perfused four-compartment bioreactor including further cultivation of remaining cells. © 2015 American Institute of Chemical Engineers.

Implantable Self-Powered Low-Level Laser Cure System for Mouse Embryonic Osteoblasts' Proliferation and Differentiation.

PubMed

Tang, Wei; Tian, Jingjing; Zheng, Qiang; Yan, Lin; Wang, Jiangxue; Li, Zhou; Wang, Zhong Lin

2015-08-25

Bone remodeling or orthodontic treatment is usually a long-term process. It is highly desirable to speed up the process for effective medical treatment. In this work, a self-powered low-level laser cure system for osteogenesis is developed using the power generated by the triboelectric nanogenerator. It is found that the system significantly accelerated the mouse embryonic osteoblasts' proliferation and differentiation, which is essential for bone and tooth healing. The system is further demonstrated to be driven by a living creature's motions, such as human walking or a mouse's breathing, suggesting its practical use as a portable or implantable clinical cure for bone remodeling or orthodontic treatment.

Preconditioning allows engraftment of mouse and human embryonic lung cells, enabling lung repair in mice.

PubMed

Rosen, Chava; Shezen, Elias; Aronovich, Anna; Klionsky, Yael Zlotnikov; Yaakov, Yasmin; Assayag, Miri; Biton, Inbal Eti; Tal, Orna; Shakhar, Guy; Ben-Hur, Herzel; Shneider, David; Vaknin, Zvi; Sadan, Oscar; Evron, Shmuel; Freud, Enrique; Shoseyov, David; Wilschanski, Michael; Berkman, Neville; Fibbe, Willem E; Hagin, David; Hillel-Karniel, Carmit; Krentsis, Irit Milman; Bachar-Lustig, Esther; Reisner, Yair

2015-08-01

Repair of injured lungs represents a longstanding therapeutic challenge. We show that human and mouse embryonic lung tissue from the canalicular stage of development (20-22 weeks of gestation for humans, and embryonic day 15-16 (E15-E16) for mouse) are enriched with progenitors residing in distinct niches. On the basis of the marked analogy to progenitor niches in bone marrow (BM), we attempted strategies similar to BM transplantation, employing sublethal radiation to vacate lung progenitor niches and to reduce stem cell competition. Intravenous infusion of a single cell suspension of canalicular lung tissue from GFP-marked mice or human fetal donors into naphthalene-injured and irradiated syngeneic or SCID mice, respectively, induced marked long-term lung chimerism. Donor type structures or 'patches' contained epithelial, mesenchymal and endothelial cells. Transplantation of differentially labeled E16 mouse lung cells indicated that these patches were probably of clonal origin from the donor. Recipients of the single cell suspension transplant exhibited marked improvement in lung compliance and tissue damping reflecting the energy dissipation in the lung tissues. Our study provides proof of concept for lung reconstitution by canalicular-stage human lung cells after preconditioning of the pulmonary niche.

Embryonic cholecystitis and defective gallbladder contraction in the Sox17-haploinsufficient mouse model of biliary atresia

PubMed Central

Fujino, Ko; Igarashi, Hitomi; Imaimatsu, Kenya; Tsunekawa, Naoki; Hirate, Yoshikazu; Kurohmaru, Masamichi; Saijoh, Yukio; Kanai-Azuma, Masami

2017-01-01

The gallbladder excretes cytotoxic bile acids into the duodenum through the cystic duct and common bile duct system. Sox17 haploinsufficiency causes biliary atresia-like phenotypes and hepatitis in late organogenesis mouse embryos, but the molecular and cellular mechanisms underlying this remain unclear. In this study, transcriptomic analyses revealed the early onset of cholecystitis in Sox17+/− embryos, together with the appearance of ectopic cystic duct-like epithelia in their gallbladders. The embryonic hepatitis showed positive correlations with the severity of cholecystitis in individual Sox17+/− embryos. Embryonic hepatitis could be induced by conditional deletion of Sox17 in the primordial gallbladder epithelia but not in fetal liver hepatoblasts. The Sox17+/− gallbladder also showed a drastic reduction in sonic hedgehog expression, leading to aberrant smooth muscle formation and defective contraction of the fetal gallbladder. The defective gallbladder contraction positively correlated with the severity of embryonic hepatitis in Sox17+/− embryos, suggesting a potential contribution of embryonic cholecystitis and fetal gallbladder contraction in the early pathogenesis of congenital biliary atresia. PMID:28432216

Ex vivo culture of mouse embryonic skin and live-imaging of melanoblast migration.

PubMed

Mort, Richard L; Keighren, Margaret; Hay, Leonard; Jackson, Ian J

2014-05-19

Melanoblasts are the neural crest derived precursors of melanocytes; the cells responsible for producing the pigment in skin and hair. Melanoblasts migrate through the epidermis of the embryo where they subsequently colonize the developing hair follicles(1,2). Neural crest cell migration is extensively studied in vitro but in vivo methods are still not well developed, especially in mammalian systems. One alternative is to use ex vivo organotypic culture(3-6). Culture of mouse embryonic skin requires the maintenance of an air-liquid interface (ALI) across the surface of the tissue(3,6). High resolution live-imaging of mouse embryonic skin has been hampered by the lack of a good method that not only maintains this ALI but also allows the culture to be inverted and therefore compatible with short working distance objective lenses and most confocal microscopes. This article describes recent improvements to a method that uses a gas permeable membrane to overcome these problems and allow high-resolution confocal imaging of embryonic skin in ex vivo culture(6). By using a melanoblast specific Cre-recombinase expressing mouse line combined with the R26YFPR reporter line we are able to fluorescently label the melanoblast population within these skin cultures. The technique allows live-imaging of melanoblasts and observation of their behavior and interactions with the tissue in which they develop. Representative results are included to demonstrate the capability to live-image 6 cultures in parallel.

Immobilization of Heparan Sulfate on Electrospun Meshes to Support Embryonic Stem Cell Culture and Differentiation*

PubMed Central

Meade, Kate A.; White, Kathryn J.; Pickford, Claire E.; Holley, Rebecca J.; Marson, Andrew; Tillotson, Donna; van Kuppevelt, Toin H.; Whittle, Jason D.; Day, Anthony J.; Merry, Catherine L. R.

2013-01-01

As our understanding of what guides the behavior of multi- and pluripotent stem cells deepens, so too does our ability to utilize certain cues to manipulate their behavior and maximize their therapeutic potential. Engineered, biologically functionalized materials have the capacity to influence stem cell behavior through a powerful combination of biological, mechanical, and topographical cues. Here, we present the development of a novel electrospun scaffold, functionalized with glycosaminoglycans (GAGs) ionically immobilized onto the fiber surface. Bound GAGs retained the ability to interact with GAG-binding molecules and, crucially, presented GAG sulfation motifs fundamental to mediating stem cell behavior. Bound GAG proved to be biologically active, rescuing the neural differentiation capacity of heparan sulfate-deficient mouse embryonic stem cells and functioning in concert with FGF4 to facilitate the formation of extensive neural processes across the scaffold surface. The combination of GAGs with electrospun scaffolds creates a biomaterial with potent applicability for the propagation and effective differentiation of pluripotent stem cells. PMID:23235146

Immobilization of heparan sulfate on electrospun meshes to support embryonic stem cell culture and differentiation.

PubMed

Meade, Kate A; White, Kathryn J; Pickford, Claire E; Holley, Rebecca J; Marson, Andrew; Tillotson, Donna; van Kuppevelt, Toin H; Whittle, Jason D; Day, Anthony J; Merry, Catherine L R

2013-02-22

As our understanding of what guides the behavior of multi- and pluripotent stem cells deepens, so too does our ability to utilize certain cues to manipulate their behavior and maximize their therapeutic potential. Engineered, biologically functionalized materials have the capacity to influence stem cell behavior through a powerful combination of biological, mechanical, and topographical cues. Here, we present the development of a novel electrospun scaffold, functionalized with glycosaminoglycans (GAGs) ionically immobilized onto the fiber surface. Bound GAGs retained the ability to interact with GAG-binding molecules and, crucially, presented GAG sulfation motifs fundamental to mediating stem cell behavior. Bound GAG proved to be biologically active, rescuing the neural differentiation capacity of heparan sulfate-deficient mouse embryonic stem cells and functioning in concert with FGF4 to facilitate the formation of extensive neural processes across the scaffold surface. The combination of GAGs with electrospun scaffolds creates a biomaterial with potent applicability for the propagation and effective differentiation of pluripotent stem cells.

Identification of Spen as a Crucial Factor for Xist Function through Forward Genetic Screening in Haploid Embryonic Stem Cells

PubMed Central

Monfort, Asun; Di Minin, Giulio; Postlmayr, Andreas; Freimann, Remo; Arieti, Fabiana; Thore, Stéphane; Wutz, Anton

2015-01-01

Summary In mammals, the noncoding Xist RNA triggers transcriptional silencing of one of the two X chromosomes in female cells. Here, we report a genetic screen for silencing factors in X chromosome inactivation using haploid mouse embryonic stem cells (ESCs) that carry an engineered selectable reporter system. This system was able to identify several candidate factors that are genetically required for chromosomal repression by Xist. Among the list of candidates, we identify the RNA-binding protein Spen, the homolog of split ends. Independent validation through gene deletion in ESCs confirms that Spen is required for gene repression by Xist. However, Spen is not required for Xist RNA localization and the recruitment of chromatin modifications, including Polycomb protein Ezh2. The identification of Spen opens avenues for further investigation into the gene-silencing pathway of Xist and shows the usefulness of haploid ESCs for genetic screening of epigenetic pathways. PMID:26190100

Embryonic mammary signature subsets are activated in Brca1-/- and basal-like breast cancers

PubMed Central

2013-01-01

Introduction Cancer is often suggested to result from development gone awry. Links between normal embryonic development and cancer biology have been postulated, but no defined genetic basis has been established. We recently published the first transcriptomic analysis of embryonic mammary cell populations. Embryonic mammary epithelial cells are an immature progenitor cell population, lacking differentiation markers, which is reflected in their very distinct genetic profiles when compared with those of their postnatal descendents. Methods We defined an embryonic mammary epithelial signature that incorporates the most highly expressed genes from embryonic mammary epithelium when compared with the postnatal mammary epithelial cells. We looked for activation of the embryonic mammary epithelial signature in mouse mammary tumors that formed in mice in which Brca1 had been conditionally deleted from the mammary epithelium and in human breast cancers to determine whether any genetic links exist between embryonic mammary cells and breast cancers. Results Small subsets of the embryonic mammary epithelial signature were consistently activated in mouse Brca1-/- tumors and human basal-like breast cancers, which encoded predominantly transcriptional regulators, cell-cycle, and actin cytoskeleton components. Other embryonic gene subsets were found activated in non-basal-like tumor subtypes and repressed in basal-like tumors, including regulators of neuronal differentiation, transcription, and cell biosynthesis. Several embryonic genes showed significant upregulation in estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and/or grade 3 breast cancers. Among them, the transcription factor, SOX11, a progenitor cell and lineage regulator of nonmammary cell types, is found highly expressed in some Brca1-/- mammary tumors. By using RNA interference to silence SOX11 expression in breast cancer cells, we found evidence that SOX11 regulates breast cancer cell proliferation and cell survival. Conclusions Specific subsets of embryonic mammary genes, rather than the entire embryonic development transcriptomic program, are activated in tumorigenesis. Genes involved in embryonic mammary development are consistently upregulated in some breast cancers and warrant further investigation, potentially in drug-discovery research endeavors. PMID:23506684

Derivation of mouse embryonic stem cell lines from tyrosine hydroxylase reporter mice crossed with a human SNCA transgenic mouse model of Parkinson's disease.

PubMed

Chumarina, Margarita; Azevedo, Carla; Bigarreau, Julie; Vignon, Clémentine; Kim, Kwang-Soo; Li, Jia-Yi; Roybon, Laurent

2017-03-01

Mouse embryonic stem cell (mESC) lines were derived by crossing heterozygous transgenic (tg) mice expressing green fluorescent protein (GFP) under the control of the rat tyrosine hydroxylase (TH) promoter, with homozygous alpha-synuclein (aSYN) mice expressing human mutant SNCA A53T under the control of the mouse Prion promoter (MoPrP), or wildtype (WT) mice. The expression of GFP and human aSYN was validated by immunocytochemistry in midbrain neuron cultures upon differentiation of mESC lines using stromal cell-derived inducing activity. These mESC lines can help to study the impact of human aSYN expression in neurons and oligodendrocytes, and also trace GFP-expressing midbrain neurons. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Generating mouse lines for lineage tracing and knockout studies.

PubMed

Kraus, Petra; Sivakamasundari, V; Xing, Xing; Lufkin, Thomas

2014-01-01

In 2007 Capecchi, Evans, and Smithies received the Nobel Prize in recognition for discovering the principles for introducing specific gene modifications in mice via embryonic stem cells, a technology, which has revolutionized the field of biomedical science allowing for the generation of genetically engineered animals. Here we describe detailed protocols based on and developed from these ground-breaking discoveries, allowing for the modification of genes not only to create mutations to study gene function but additionally to modify genes with fluorescent markers, thus permitting the isolation of specific rare wild-type and mutant cell types for further detailed analysis at the biochemical, pathological, and genomic levels.

Reverse engineering a mouse embryonic stem cell-specific transcriptional network reveals a new modulator of neuronal differentiation

PubMed Central

De Cegli, Rossella; Iacobacci, Simona; Flore, Gemma; Gambardella, Gennaro; Mao, Lei; Cutillo, Luisa; Lauria, Mario; Klose, Joachim; Illingworth, Elizabeth; Banfi, Sandro; di Bernardo, Diego

2013-01-01

Gene expression profiles can be used to infer previously unknown transcriptional regulatory interaction among thousands of genes, via systems biology ‘reverse engineering’ approaches. We ‘reverse engineered’ an embryonic stem (ES)-specific transcriptional network from 171 gene expression profiles, measured in ES cells, to identify master regulators of gene expression (‘hubs’). We discovered that E130012A19Rik (E13), highly expressed in mouse ES cells as compared with differentiated cells, was a central ‘hub’ of the network. We demonstrated that E13 is a protein-coding gene implicated in regulating the commitment towards the different neuronal subtypes and glia cells. The overexpression and knock-down of E13 in ES cell lines, undergoing differentiation into neurons and glia cells, caused a strong up-regulation of the glutamatergic neurons marker Vglut2 and a strong down-regulation of the GABAergic neurons marker GAD65 and of the radial glia marker Blbp. We confirmed E13 expression in the cerebral cortex of adult mice and during development. By immuno-based affinity purification, we characterized protein partners of E13, involved in the Polycomb complex. Our results suggest a role of E13 in regulating the division between glutamatergic projection neurons and GABAergic interneurons and glia cells possibly by epigenetic-mediated transcriptional regulation. PMID:23180766

EMBRYONIC PALATAL RESPONSES TO TERATOGENS IN SERUM-FREE ORGAN CULTURE

EPA Science Inventory

This study examines development of rat, mouse and human embryonic palates in submerged, serum-free organ culture. he concentration-response profiles for retinoic acid (RA), triamcinolone (TRI), hydrocortisone (HC), dexamethasone (DEX), and 2,3,7,11- tetrachlorodibenzo-p-dioxin (T...

Akt Suppression of TGFβ Signaling Contributes to the Maintenance of Vascular Identity in Embryonic Stem Cell-Derived Endothelial Cells

PubMed Central

Israely, Edo; Ginsberg, Michael; Nolan, Daniel; Ding, Bi-Sen; James, Daylon; Elemento, Olivier; Rafii, Shahin; Rabbany, Sina Y

2016-01-01

The ability to generate and maintain stable in vitro cultures of mouse endothelial cells (EC) has great potential for genetic dissection of the numerous pathologies involving vascular dysfunction as well as therapeutic applications. However, previous efforts at achieving sustained cultures of primary stable murine vascular cells have fallen short, and the cellular requirements for EC maintenance in vitro remain undefined. In this study, we have generated vascular ECs from mouse embryonic stem (ES) cells, and show that active Akt is essential to their survival and propagation as homogeneous monolayers in vitro. These cells harbor the phenotypical, biochemical, and functional characteristics of ECs, and expand throughout long-term cultures, while maintaining their angiogenic capacity. Moreover, Akt-transduced embryonic ECs form functional perfused vessels in vivo that anastomose with host blood vessels. We provide evidence for a novel function of Akt in stabilizing EC identity, whereby the activated form of the protein protects mouse ES cell-derived ECs from TGFβ-mediated transdifferentiation by downregulating SMAD3. These findings identify a role for Akt in regulating the developmental potential of ES cell-derived ECs, and demonstrate that active Akt maintains endothelial identity in embryonic ECs by interfering with active TGFβ-mediated processes that would ordinarily usher these cells to alternate fates. PMID:23963623

Mouse cloning and somatic cell reprogramming using electrofused blastomeres.

PubMed

Riaz, Amjad; Zhao, Xiaoyang; Dai, Xiangpeng; Li, Wei; Liu, Lei; Wan, Haifeng; Yu, Yang; Wang, Liu; Zhou, Qi

2011-05-01

Mouse cloning from fertilized eggs can assist development of approaches for the production of "genetically tailored" human embryonic stem (ES) cell lines that are not constrained by the limitations of oocyte availability. However, to date only zygotes have been successfully used as recipients of nuclei from terminally differentiated somatic cell donors leading to ES cell lines. In fertility clinics, embryos of advanced embryonic stages are usually stored for future use, but their ability to support the derivation of ES cell lines via somatic nuclear transfer has not yet been proved. Here, we report that two-cell stage electrofused mouse embryos, arrested in mitosis, can support developmental reprogramming of nuclei from donor cells ranging from blastomeres to somatic cells. Live, full-term cloned pups from embryonic donors, as well as pluripotent ES cell lines from embryonic or somatic donors, were successfully generated from these reconstructed embryos. Advanced stage pre-implantation embryos were unable to develop normally to term after electrofusion and transfer of a somatic cell nucleus, indicating that discarded pre-implantation human embryos could be an important resource for research that minimizes the ethical concerns for human therapeutic cloning. Our approach provides an attractive and practical alternative to therapeutic cloning using donated oocytes for the generation of patient-specific human ES cell lines.

Akt suppression of TGFβ signaling contributes to the maintenance of vascular identity in embryonic stem cell-derived endothelial cells.

PubMed

Israely, Edo; Ginsberg, Michael; Nolan, Daniel; Ding, Bi-Sen; James, Daylon; Elemento, Olivier; Rafii, Shahin; Rabbany, Sina Y

2014-01-01

The ability to generate and maintain stable in vitro cultures of mouse endothelial cells (ECs) has great potential for genetic dissection of the numerous pathologies involving vascular dysfunction as well as therapeutic applications. However, previous efforts at achieving sustained cultures of primary stable murine vascular cells have fallen short, and the cellular requirements for EC maintenance in vitro remain undefined. In this study, we have generated vascular ECs from mouse embryonic stem (ES) cells and show that active Akt is essential to their survival and propagation as homogeneous monolayers in vitro. These cells harbor the phenotypical, biochemical, and functional characteristics of ECs and expand throughout long-term cultures, while maintaining their angiogenic capacity. Moreover, Akt-transduced embryonic ECs form functional perfused vessels in vivo that anastomose with host blood vessels. We provide evidence for a novel function of Akt in stabilizing EC identity, whereby the activated form of the protein protects mouse ES cell-derived ECs from TGFβ-mediated transdifferentiation by downregulating SMAD3. These findings identify a role for Akt in regulating the developmental potential of ES cell-derived ECs and demonstrate that active Akt maintains endothelial identity in embryonic ECs by interfering with active TGFβ-mediated processes that would ordinarily usher these cells to alternate fates. © AlphaMed Press.

A novel toxicogenomics-based approach to categorize (non-)genotoxic carcinogens.

PubMed

Schaap, Mirjam M; Wackers, Paul F K; Zwart, Edwin P; Huijskens, Ilse; Jonker, Martijs J; Hendriks, Giel; Breit, Timo M; van Steeg, Harry; van de Water, Bob; Luijten, Mirjam

2015-12-01

Alternative methods to detect non-genotoxic carcinogens are urgently needed, as this class of carcinogens goes undetected in the current testing strategy for carcinogenicity under REACH. A complicating factor is that non-genotoxic carcinogens act through several distinctive modes of action, which makes prediction of their carcinogenic property difficult. We have recently demonstrated that gene expression profiling in primary mouse hepatocytes is a useful approach to categorize non-genotoxic carcinogens according to their modes of action. In the current study, we improved the methods used for analysis and added mouse embryonic stem cells as a second in vitro test system, because of their features complementary to hepatocytes. Our approach involved an unsupervised analysis based on the 30 most significantly up- and down-regulated genes per chemical. Mouse embryonic stem cells and primary mouse hepatocytes were exposed to a selected set of chemicals and subsequently subjected to gene expression profiling. We focused on non-genotoxic carcinogens, but also included genotoxic carcinogens and non-carcinogens to test the robustness of this approach. Application of the optimized comparison approach resulted in improved categorization of non-genotoxic carcinogens. Mouse embryonic stem cells were a useful addition, especially for genotoxic substances, but also for detection of non-genotoxic carcinogens that went undetected by primary hepatocytes. The approach presented here is an important step forward to categorize chemicals, especially those that are carcinogenic.

Vitamin K2 biosynthetic enzyme, UBIAD1 is essential for embryonic development of mice.

PubMed

Nakagawa, Kimie; Sawada, Natsumi; Hirota, Yoshihisa; Uchino, Yuri; Suhara, Yoshitomo; Hasegawa, Tomoka; Amizuka, Norio; Okamoto, Tadashi; Tsugawa, Naoko; Kamao, Maya; Funahashi, Nobuaki; Okano, Toshio

2014-01-01

UbiA prenyltransferase domain containing 1 (UBIAD1) is a novel vitamin K2 biosynthetic enzyme screened and identified from the human genome database. UBIAD1 has recently been shown to catalyse the biosynthesis of Coenzyme Q10 (CoQ10) in zebrafish and human cells. To investigate the function of UBIAD1 in vivo, we attempted to generate mice lacking Ubiad1, a homolog of human UBIAD1, by gene targeting. Ubiad1-deficient (Ubiad1(-/-)) mouse embryos failed to survive beyond embryonic day 7.5, exhibiting small-sized body and gastrulation arrest. Ubiad1(-/-) embryonic stem (ES) cells failed to synthesize vitamin K2 but were able to synthesize CoQ9, similar to wild-type ES cells. Ubiad1(+/-) mice developed normally, exhibiting normal growth and fertility. Vitamin K2 tissue levels and synthesis activity were approximately half of those in the wild-type, whereas CoQ9 tissue levels and synthesis activity were similar to those in the wild-type. Similarly, UBIAD1 expression and vitamin K2 synthesis activity of mouse embryonic fibroblasts prepared from Ubiad1(+/-) E15.5 embryos were approximately half of those in the wild-type, whereas CoQ9 levels and synthesis activity were similar to those in the wild-type. Ubiad1(-/-) mouse embryos failed to be rescued, but their embryonic lifespans were extended to term by oral administration of MK-4 or CoQ10 to pregnant Ubiad1(+/-) mice. These results suggest that UBIAD1 is responsible for vitamin K2 synthesis but may not be responsible for CoQ9 synthesis in mice. We propose that UBIAD1 plays a pivotal role in embryonic development by synthesizing vitamin K2, but may have additional functions beyond the biosynthesis of vitamin K2.

Embryonic Mutant Huntingtin Aggregate Formation in Mouse Models of Huntington's Disease.

PubMed

Osmand, Alexander P; Bichell, Terry Jo; Bowman, Aaron B; Bates, Gillian P

2016-12-15

The role of aggregate formation in the pathophysiology of Huntington's disease (HD) remains uncertain. However, the temporal appearance of aggregates tends to correlate with the onset of symptoms and the numbers of neuropil aggregates correlate with the progression of clinical disease. Using highly sensitive immunohistochemical methods we have detected the appearance of diffuse aggregates during embryonic development in the R6/2 and YAC128 mouse models of HD. These are initially seen in developing axonal tracts and appear to spread throughout the cerebrum in the early neonate.

Engineering of a Histone-Recognition Domain in Dnmt3a Alters the Epigenetic Landscape and Phenotypic Features of Mouse ESCs.

PubMed

Noh, Kyung-Min; Wang, Haibo; Kim, Hyunjae R; Wenderski, Wendy; Fang, Fang; Li, Charles H; Dewell, Scott; Hughes, Stephen H; Melnick, Ari M; Patel, Dinshaw J; Li, Haitao; Allis, C David

2015-07-02

Histone modification and DNA methylation are associated with varying epigenetic "landscapes," but detailed mechanistic and functional links between the two remain unclear. Using the ATRX-DNMT3-DNMT3L (ADD) domain of the DNA methyltransferase Dnmt3a as a paradigm, we apply protein engineering to dissect the molecular interactions underlying the recruitment of this enzyme to specific regions of chromatin in mouse embryonic stem cells (ESCs). By rendering the ADD domain insensitive to histone modification, specifically H3K4 methylation or H3T3 phosphorylation, we demonstrate the consequence of dysregulated Dnmt3a binding and activity. Targeting of a Dnmt3a mutant to H3K4me3 promoters decreases gene expression in a subset of developmental genes and alters ESC differentiation, whereas aberrant binding of another mutant to H3T3ph during mitosis promotes chromosome instability. Our studies support the general view that histone modification "reading" and DNA methylation are closely coupled in mammalian cells, and suggest an avenue for the functional assessment of chromatin-associated proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

Three-dimensional microCT imaging of murine embryonic development from immediate post-implantation to organogenesis: application for phenotyping analysis of early embryonic lethality in mutant animals.

PubMed

Ermakova, Olga; Orsini, Tiziana; Gambadoro, Alessia; Chiani, Francesco; Tocchini-Valentini, Glauco P

2018-04-01

In this work, we applied three-dimensional microCT imaging to study murine embryogenesis in the range from immediate post-implantation period (embryonic day 5.5) to mid-gestation (embryonic day 12.5) with the resolution up to 1.4 µm/voxel. Also, we introduce an imaging procedure for non-invasive volumetric estimation of an entire litter of embryos within the maternal uterine structures. This method allows for an accurate, detailed and systematic morphometric analysis of both embryonic and extra-embryonic components during embryogenesis. Three-dimensional imaging of unperturbed embryos was performed to visualize the egg cylinder, primitive streak, gastrulation and early organogenesis stages of murine development in the C57Bl6/N mouse reference strain. Further, we applied our microCT imaging protocol to determine the earliest point when embryonic development is arrested in a mouse line with knockout for tRNA splicing endonuclease subunit Tsen54 gene. Our analysis determined that the embryonic development in Tsen54 null embryos does not proceed beyond implantation. We demonstrated that application of microCT imaging to entire litter of non-perturbed embryos greatly facilitate studies to unravel gene function during early embryogenesis and to determine the precise point at which embryonic development is arrested in mutant animals. The described method is inexpensive, does not require lengthy embryos dissection and can be applicable for detailed analysis of mutant mice at laboratory scale as well as for high-throughput projects.

Knockout of the PKN Family of Rho Effector Kinases Reveals a Non-redundant Role for PKN2 in Developmental Mesoderm Expansion

PubMed Central

Quétier, Ivan; Marshall, Jacqueline J.T.; Spencer-Dene, Bradley; Lachmann, Sylvie; Casamassima, Adele; Franco, Claudio; Escuin, Sarah; Worrall, Joseph T.; Baskaran, Priththivika; Rajeeve, Vinothini; Howell, Michael; Copp, Andrew J.; Stamp, Gordon; Rosewell, Ian; Cutillas, Pedro; Gerhardt, Holger; Parker, Peter J.; Cameron, Angus J.M.

2016-01-01

Summary In animals, the protein kinase C (PKC) family has expanded into diversely regulated subgroups, including the Rho family-responsive PKN kinases. Here, we describe knockouts of all three mouse PKN isoforms and reveal that PKN2 loss results in lethality at embryonic day 10 (E10), with associated cardiovascular and morphogenetic defects. The cardiovascular phenotype was not recapitulated by conditional deletion of PKN2 in endothelial cells or the developing heart. In contrast, inducible systemic deletion of PKN2 after E7 provoked collapse of the embryonic mesoderm. Furthermore, mouse embryonic fibroblasts, which arise from the embryonic mesoderm, depend on PKN2 for proliferation and motility. These cellular defects are reflected in vivo as dependence on PKN2 for mesoderm proliferation and neural crest migration. We conclude that failure of the mesoderm to expand in the absence of PKN2 compromises cardiovascular integrity and development, resulting in lethality. PMID:26774483

Knockout of the PKN Family of Rho Effector Kinases Reveals a Non-redundant Role for PKN2 in Developmental Mesoderm Expansion.

PubMed

Quétier, Ivan; Marshall, Jacqueline J T; Spencer-Dene, Bradley; Lachmann, Sylvie; Casamassima, Adele; Franco, Claudio; Escuin, Sarah; Worrall, Joseph T; Baskaran, Priththivika; Rajeeve, Vinothini; Howell, Michael; Copp, Andrew J; Stamp, Gordon; Rosewell, Ian; Cutillas, Pedro; Gerhardt, Holger; Parker, Peter J; Cameron, Angus J M

2016-01-26

In animals, the protein kinase C (PKC) family has expanded into diversely regulated subgroups, including the Rho family-responsive PKN kinases. Here, we describe knockouts of all three mouse PKN isoforms and reveal that PKN2 loss results in lethality at embryonic day 10 (E10), with associated cardiovascular and morphogenetic defects. The cardiovascular phenotype was not recapitulated by conditional deletion of PKN2 in endothelial cells or the developing heart. In contrast, inducible systemic deletion of PKN2 after E7 provoked collapse of the embryonic mesoderm. Furthermore, mouse embryonic fibroblasts, which arise from the embryonic mesoderm, depend on PKN2 for proliferation and motility. These cellular defects are reflected in vivo as dependence on PKN2 for mesoderm proliferation and neural crest migration. We conclude that failure of the mesoderm to expand in the absence of PKN2 compromises cardiovascular integrity and development, resulting in lethality. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Non-destructive monitoring of mouse embryo development and its qualitative evaluation at the molecular level using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Ishigaki, Mika; Hashimoto, Kosuke; Sato, Hidetoshi; Ozaki, Yukihiro

2017-03-01

Current research focuses on embryonic development and quality not only by considering fundamental biology, but also by aiming to improve assisted reproduction technologies, such as in vitro fertilization. In this study, we explored the development of mouse embryo and its quality based on molecular information, obtained nondestructively using Raman spectroscopy. The detailed analysis of Raman spectra measured in situ during embryonic development revealed a temporary increase in protein content after fertilization. Proteins with a β-sheet structure—present in the early stages of embryonic development—are derived from maternal oocytes, while α-helical proteins are additionally generated by switching on a gene after fertilization. The transition from maternal to embryonic control during development can be non-destructively profiled, thus facilitating the in situ assessment of structural changes and component variation in proteins generated by metabolic activity. Furthermore, it was indicated that embryos with low-grade morphology had high concentrations of lipids and hydroxyapatite. This technique could be used for embryo quality testing in the future.

In vitro organogenesis of gut-like structures from mouse embryonic stem cells.

PubMed

Kuwahara, M; Ogaeri, T; Matsuura, R; Kogo, H; Fujimoto, T; Torihashi, S

2004-04-01

Embryonic stem (ES) cells have pluripotency and give rise to many cell types and tissues, including representatives of all three germ layers in the embryo. We have reported previously that mouse ES cells formed contracting gut-like organs from embryoid bodies (EBs). These gut-like structures contracted spontaneously, and had large lumens surrounded by three layers, i.e. epithelium, lamina propria and muscularis. Ganglia were scattered along the periphery, and interstitial cells of Cajal (ICC) were distributed among the smooth muscle cells. In the present study, to determine whether they can be a model of gut organogenesis, we investigated the formation process of the gut-like structures in comparison with embryonic gut development. As a result, we found that the fundamental process of formation in vitro was similar to embryonic gut development in vivo. The result indicates that the gut-like structure is a useful tool not only for developmental study to determine the factors that induce gut organogenesis, but also for studies of enteric neurone and ICC development.

Treatment of hypoxic-ischemic encephalopathy in mouse by transplantation of embryonic stem cell-derived cells.

PubMed

Ma, Jie; Wang, Yu; Yang, Jianhua; Yang, Min; Chang, Keun-A; Zhang, Linhua; Jiang, Feng; Li, Yi; Zhang, Zhonggong; Heo, Chaejeong; Suh, Yoo-Hun

2007-07-01

A 7-day-old hypoxic-ischemic encephalopathy (HIE) mouse model was used to study the effect of transplantation of embryonic stem (ES) cell-derived cells on the HIE. After the inducement in vitro, the ES cell-derived cells expressed Nestin and MAP-2, rather than GFAP mRNA. After transplantation, ES cell-derived cells can survive, migrate into the injury site, and specifically differentiate into neurons, showing improvement of the learning ability and memory of the HIE mouse at 8 months post-transplantation. The non-grafted HIE mouse brain showed typical pathological changes in the hippocampus and cerebral cortex, where the number of neurons was reduced, while in the cell graft group, number of the neurons increased in the same regions. Although further study is necessary to elucidate the precise mechanisms responsible for this functional recovery, we believe that ES cells have advantages for use as a donor source in HIE.

Generation of an immortalized mouse embryonic palatal mesenchyme cell line

PubMed Central

Soriano, Philippe

2017-01-01

Palatogenesis is a complex morphogenetic process, disruptions in which result in highly prevalent birth defects in humans. In recent decades, the use of model systems such as genetically-modified mice, mouse palatal organ cultures and primary mouse embryonic palatal mesenchyme (MEPM) cultures has provided significant insight into the molecular and cellular defects underlying cleft palate. However, drawbacks in each of these systems have prevented high-throughput, large-scale studies of palatogenesis in vitro. Here, we report the generation of an immortalized MEPM cell line that maintains the morphology, migration ability, transcript expression and responsiveness to exogenous growth factors of primary MEPM cells, with increased proliferative potential over primary cultures. The immortalization method described in this study will facilitate the generation of palatal mesenchyme cells with an unlimited capacity for expansion from a single genetically-modified mouse embryo and enable mechanistic studies of palatogenesis that have not been possible using primary culture. PMID:28582446

Structure-based discovery of NANOG variant with enhanced properties to promote self-renewal and reprogramming of pluripotent stem cells

DOE PAGES

Hayashi, Yohei; Caboni, Laura; Das, Debanu; ...

2015-03-30

NANOG (from Irish mythology Tír na nÓg) transcription factor plays a central role in maintaining pluripotency, cooperating with OCT4 (also known as POU5F1 or OCT3/4), SOX2, and other pluripotency factors. Although the physiological roles of the NANOG protein have been extensively explored, biochemical and biophysical properties in relation to its structural analysis are poorly understood. Here we determined the crystal structure of the human NANOG homeodomain (hNANOG HD) bound to an OCT4 promoter DNA, which revealed amino acid residues involved in DNA recognition that are likely to be functionally important. We generated a series of hNANOG HD alanine substitution mutantsmore » based on the protein–DNA interaction and evolutionary conservation and determined their biological activities. Some mutant proteins were less stable, resulting in loss or decreased affinity for DNA binding. Overexpression of the orthologous mouse NANOG (mNANOG) mutants failed to maintain self-renewal of mouse embryonic stem cells without leukemia inhibitory factor. These results suggest that these residues are critical for NANOG transcriptional activity. Interestingly, one mutant, hNANOG L122A, conversely enhanced protein stability and DNA-binding affinity. The mNANOG L122A, when overexpressed in mouse embryonic stem cells, maintained their expression of self-renewal markers even when retinoic acid was added to forcibly drive differentiation. When overexpressed in epiblast stem cells or human induced pluripotent stem cells, the L122A mutants enhanced reprogramming into ground-state pluripotency. These findings indicate that structural and biophysical information on key transcriptional factors provides insights into the manipulation of stem cell behaviors and a framework for rational protein engineering.« less

Structure-based discovery of NANOG variant with enhanced properties to promote self-renewal and reprogramming of pluripotent stem cells

PubMed Central

Hayashi, Yohei; Caboni, Laura; Das, Debanu; Yumoto, Fumiaki; Clayton, Thomas; Deller, Marc C.; Nguyen, Phuong; Farr, Carol L.; Chiu, Hsiu-Ju; Miller, Mitchell D.; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Tomoda, Kiichiro; Conklin, Bruce R.; Wilson, Ian A.; Yamanaka, Shinya; Fletterick, Robert J.

2015-01-01

NANOG (from Irish mythology Tír na nÓg) transcription factor plays a central role in maintaining pluripotency, cooperating with OCT4 (also known as POU5F1 or OCT3/4), SOX2, and other pluripotency factors. Although the physiological roles of the NANOG protein have been extensively explored, biochemical and biophysical properties in relation to its structural analysis are poorly understood. Here we determined the crystal structure of the human NANOG homeodomain (hNANOG HD) bound to an OCT4 promoter DNA, which revealed amino acid residues involved in DNA recognition that are likely to be functionally important. We generated a series of hNANOG HD alanine substitution mutants based on the protein–DNA interaction and evolutionary conservation and determined their biological activities. Some mutant proteins were less stable, resulting in loss or decreased affinity for DNA binding. Overexpression of the orthologous mouse NANOG (mNANOG) mutants failed to maintain self-renewal of mouse embryonic stem cells without leukemia inhibitory factor. These results suggest that these residues are critical for NANOG transcriptional activity. Interestingly, one mutant, hNANOG L122A, conversely enhanced protein stability and DNA-binding affinity. The mNANOG L122A, when overexpressed in mouse embryonic stem cells, maintained their expression of self-renewal markers even when retinoic acid was added to forcibly drive differentiation. When overexpressed in epiblast stem cells or human induced pluripotent stem cells, the L122A mutants enhanced reprogramming into ground-state pluripotency. These findings demonstrate that structural and biophysical information on key transcriptional factors provides insights into the manipulation of stem cell behaviors and a framework for rational protein engineering. PMID:25825768

Structure-based discovery of NANOG variant with enhanced properties to promote self-renewal and reprogramming of pluripotent stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashi, Yohei; Caboni, Laura; Das, Debanu

NANOG (from Irish mythology Tír na nÓg) transcription factor plays a central role in maintaining pluripotency, cooperating with OCT4 (also known as POU5F1 or OCT3/4), SOX2, and other pluripotency factors. Although the physiological roles of the NANOG protein have been extensively explored, biochemical and biophysical properties in relation to its structural analysis are poorly understood. Here we determined the crystal structure of the human NANOG homeodomain (hNANOG HD) bound to an OCT4 promoter DNA, which revealed amino acid residues involved in DNA recognition that are likely to be functionally important. We generated a series of hNANOG HD alanine substitution mutantsmore » based on the protein–DNA interaction and evolutionary conservation and determined their biological activities. Some mutant proteins were less stable, resulting in loss or decreased affinity for DNA binding. Overexpression of the orthologous mouse NANOG (mNANOG) mutants failed to maintain self-renewal of mouse embryonic stem cells without leukemia inhibitory factor. These results suggest that these residues are critical for NANOG transcriptional activity. Interestingly, one mutant, hNANOG L122A, conversely enhanced protein stability and DNA-binding affinity. The mNANOG L122A, when overexpressed in mouse embryonic stem cells, maintained their expression of self-renewal markers even when retinoic acid was added to forcibly drive differentiation. When overexpressed in epiblast stem cells or human induced pluripotent stem cells, the L122A mutants enhanced reprogramming into ground-state pluripotency. These findings indicate that structural and biophysical information on key transcriptional factors provides insights into the manipulation of stem cell behaviors and a framework for rational protein engineering.« less

R/L, a double reporter mouse line that expresses luciferase gene upon Cre-mediated excision, followed by inactivation of mRFP expression.

PubMed

Jia, Junshuang; Lin, Xiaolin; Lin, Xia; Lin, Taoyan; Chen, Bangzhu; Hao, Weichao; Cheng, Yushuang; Liu, Yu; Dian, Meijuan; Yao, Kaitai; Xiao, Dong; Gu, Weiwang

2016-10-01

The Cre/loxP system has become an important tool for the conditional gene knockout and conditional gene expression in genetically engineered mice. The applications of this system depend on transgenic reporter mouse lines that provide Cre recombinase activity with a defined cell type-, tissue-, or developmental stage-specificity. To develop a sensitive assay for monitoring Cre-mediated DNA excisions in mice, we generated Cre-mediated excision reporter mice, designated R/L mice (R/L: mRFP(monomeric red fluorescent protein)/luciferase), express mRFP throughout embryonic development and adult stages, while Cre-mediated excision deletes a loxP-flanked mRFP reporter gene and STOP sequence, thereby activating the expression of the second reporter gene luciferase, as assayed by in vivo and ex vivo bioluminescence imaging. After germ line deletion of the floxed mRFP and STOP sequence in R/L mice by EIIa-Cre mice, the resulting luciferase transgenic mice in which the loxP-mRFP-STOP-loxP cassette is excised from all cells express luciferase in all tissues and organs examined. The expression of luciferase transgene was activated in liver of RL/Alb-Cre double transgenic mice and in brain of RL/Nestin-Cre double transgenic mice when R/L reporter mice were mated with Alb-Cre mice and Nestin-Cre mice, respectively. Our findings reveal that the double reporter R/L mouse line is able to indicate the occurrence of Cre-mediated excision from early embryonic to adult lineages. Taken together, these findings demonstrate that the R/L mice serve as a sensitive reporter for Cre-mediated DNA excision both in living animals and in organs, tissues, and cells following necropsy.

Pluripotent stem cells and livestock genetic engineering

PubMed Central

Soto, Delia A.

2016-01-01

The unlimited proliferative ability and capacity to contribute to germline chimeras make pluripotent embryonic stem cells (ESCs) perfect candidates for complex genetic engineering. The utility of ESCs is best exemplified by the numerous genetic models that have been developed in mice, for which such cells are readily available. However, the traditional systems for mouse genetic engineering may not be practical for livestock species, as it requires several generations of mating and selection in order to establish homozygous founders. Nevertheless, the self-renewal and pluripotent characteristics of ESCs could provide advantages for livestock genetic engineering such as ease of genetic manipulation and improved efficiency of cloning by nuclear transplantation. These advantages have resulted in many attempts to isolate livestock ESCs, yet it has been generally concluded that the culture conditions tested so far are not supportive of livestock ESCs self-renewal and proliferation. In contrast, there are numerous reports of derivation of livestock induced pluripotent stem cells (iPSCs), with demonstrated capacity for long term proliferation and in vivo pluripotency, as indicated by teratoma formation assay. However, to what extent these iPSCs represent fully reprogrammed PSCs remains controversial, as most livestock iPSCs depend on continuous expression of reprogramming factors. Moreover, germline chimerism has not been robustly demonstrated, with only one successful report with very low efficiency. Therefore, even 34 years after derivation of mouse ESCs and their extensive use in the generation of genetic models, the livestock genetic engineering field can stand to gain enormously from continued investigations into the derivation and application of ESCs and iPSCs. PMID:26894405

Pluripotent stem cells and livestock genetic engineering.

PubMed

Soto, Delia A; Ross, Pablo J

2016-06-01

The unlimited proliferative ability and capacity to contribute to germline chimeras make pluripotent embryonic stem cells (ESCs) perfect candidates for complex genetic engineering. The utility of ESCs is best exemplified by the numerous genetic models that have been developed in mice, for which such cells are readily available. However, the traditional systems for mouse genetic engineering may not be practical for livestock species, as it requires several generations of mating and selection in order to establish homozygous founders. Nevertheless, the self-renewal and pluripotent characteristics of ESCs could provide advantages for livestock genetic engineering such as ease of genetic manipulation and improved efficiency of cloning by nuclear transplantation. These advantages have resulted in many attempts to isolate livestock ESCs, yet it has been generally concluded that the culture conditions tested so far are not supportive of livestock ESCs self-renewal and proliferation. In contrast, there are numerous reports of derivation of livestock induced pluripotent stem cells (iPSCs), with demonstrated capacity for long term proliferation and in vivo pluripotency, as indicated by teratoma formation assay. However, to what extent these iPSCs represent fully reprogrammed PSCs remains controversial, as most livestock iPSCs depend on continuous expression of reprogramming factors. Moreover, germline chimerism has not been robustly demonstrated, with only one successful report with very low efficiency. Therefore, even 34 years after derivation of mouse ESCs and their extensive use in the generation of genetic models, the livestock genetic engineering field can stand to gain enormously from continued investigations into the derivation and application of ESCs and iPSCs.

New frontiers in gene targeting and cloning: success, application and challenges in domestic animals and human embryonic stem cells.

PubMed

Denning, Chris; Priddle, Helen

2003-07-01

Until recently, precise modification of the animal genome by gene targeting was restricted to the mouse because germline competent embryonic stem cells are not available in any other mammalian species. Nuclear transfer (NT) technology now provides an alternative route for cell-based transgenesis in domestic species, offering new opportunities in genetic modification. Livestock that produce human therapeutic proteins in their milk, have organs suitable for xenotransplantation, or that could provide resistance to diseases such as spongiform encephalopathies have been produced by NT from engineered, cultured somatic cells. However, improvements in the efficiency of somatic cell gene targeting and a greater understanding of the reprogramming events that occur during NT are required for the routine application of what is currently an inefficient process. The ability to reprogramme and genetically manipulate cells will also be crucial for full exploitation of human embryonic stem (hES) cells, which offer unparalleled opportunities in human health and biotechnology. Particularly pertinent are directed differentiation of hES lines to specific cell lineages, production of cells that evade the patient's immune system and ensuring the safety of ensuing transplants. This review will discuss some of the successes, applications and challenges facing gene targeting in livestock and hES cells.

Regulation of lung branching morphogenesis by bombesin-like peptides and neutral endopeptidase.

PubMed

Aguayo, S M; Schuyler, W E; Murtagh, J J; Roman, J

1994-06-01

The expression of bombesin-like peptides (BLPs) by pulmonary neuroendocrine cells is transiently upregulated during lung development. A functional role for BLPs is supported by their ability to stimulate lung growth and maturation both in vitro and in vivo during the late stages of lung development. In addition, the cell membrane-associated enzyme CD10/neutral endopeptidase 24.11 (CD10/NEP), which inactivates BLPs and other regulatory peptides, is also expressed by developing lungs and modulates the stimulatory effects of BLPs on lung growth and maturation. We hypothesized that, in addition to expressing BLPs and CD10/NEP, embryonic lungs must express BLP receptors, and that BLPs may also regulate processes that occur during early lung development such as branching morphogenesis. Using reverse transcriptase-polymerase chain reaction and oligonucleotide primers designed for amplifying a BLP receptor originally isolated from Swiss 3T3 mouse fibroblasts, we found that embryonic mouse lungs express a similar BLP receptor mRNA during the pseudoglandular stage of lung development when branching morphogenesis take place. Subsequently, we evaluated the effects of ligands for this BLP receptor using embryonic mouse lungs in an in vitro model of lung branching morphogenesis. We found that, in comparison with control lungs, treatment with bombesin (1 to 100 nM) resulted in a modest increase in clefts or branching points. In contrast, embryonic mouse lungs treated with the BLP analog [Leu13-psi(CH2NH)Leu14]bombesin (1 microM), which also binds to this BLP receptor but has predominantly antagonistic effects, demonstrated fewer branching points.(ABSTRACT TRUNCATED AT 250 WORDS)

SIRT1 deficiency compromises mouse embryonic stem cell hematopoietic differentiation, and embryonic and adult hematopoiesis in the mouse

PubMed Central

Ou, Xuan; Chae, Hee-Don; Wang, Rui-Hong; Shelley, William C.; Cooper, Scott; Taylor, Tammi; Kim, Young-June; Deng, Chu-Xia; Yoder, Mervin C.

2011-01-01

SIRT1 is a founding member of a sirtuin family of 7 proteins and histone deacetylases. It is involved in cellular resistance to stress, metabolism, differentiation, aging, and tumor suppression. SIRT1−/− mice demonstrate embryonic and postnatal development defects. We examined hematopoietic and endothelial cell differentiation of SIRT1−/− mouse embryonic stem cells (ESCs) in vitro, and hematopoietic progenitors in SIRT1+/++/−, and −/− mice. SIRT1−/− ESCs formed fewer mature blast cell colonies. Replated SIRT1−/− blast colony-forming cells demonstrated defective hematopoietic potential. Endothelial cell production was unaltered, but there were defects in formation of a primitive vascular network from SIRT1−/−-derived embryoid bodies. Development of primitive and definitive progenitors derived from SIRT1−/− ESCs were also delayed and/or defective. Differentiation delay/defects were associated with delayed capacity to switch off Oct4, Nanog and Fgf5 expression, decreased β-H1 globin, β-major globin, and Scl gene expression, and reduced activation of Erk1/2. Ectopic expression of SIRT1 rescued SIRT1−/− ESC differentiation deficiencies. SIRT1−/− yolk sacs manifested fewer primitive erythroid precursors. SIRT1−/− and SIRT1+/− adult marrow had decreased numbers and cycling of hematopoietic progenitors, effects more apparent at 5%, than at 20%, oxygen tension, and these progenitors survived less well in vitro under conditions of delayed growth factor addition. This suggests a role for SIRT1 in ESC differentiation and mouse hematopoiesis. PMID:20966168

MicroRNA-127 Promotes Mesendoderm Differentiation of Mouse Embryonic Stem Cells by Targeting Left-Right Determination Factor 2.

PubMed

Ma, Haixia; Lin, Yu; Zhao, Zhen-Ao; Lu, Xukun; Yu, Yang; Zhang, Xiaoxin; Wang, Qiang; Li, Lei

2016-06-03

Specification of the three germ layers is a fundamental process and is essential for the establishment of organ rudiments. Multiple genetic and epigenetic factors regulate this dynamic process; however, the function of specific microRNAs in germ layer differentiation remains unknown. In this study, we established that microRNA-127 (miR-127) is related to germ layer specification via microRNA array analysis of isolated three germ layers of E7.5 mouse embryos and was verified through differentiation of mouse embryonic stem cells. miR-127 is highly expressed in endoderm and primitive streak. Overexpression of miR-127 increases and inhibition of miR-127 decreases the expression of mesendoderm markers. We further show that miR-127 promotes mesendoderm differentiation through the nodal pathway, a determinative signaling pathway in early embryogenesis. Using luciferase reporter assay, left-right determination factor 2 (Lefty2), an antagonist of nodal, is identified to be a novel target of miR-127. Furthermore, the role of miR-127 in mesendoderm differentiation is attenuated by Lefty2 overexpression. Altogether, our results indicate that miR-127 accelerates mesendoderm differentiation of mouse embryonic stem cells through nodal signaling by targeting Lefty2. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Use of “MGE Enhancers” for Labeling and Selection of Embryonic Stem Cell-Derived Medial Ganglionic Eminence (MGE) Progenitors and Neurons

PubMed Central

Chen, Ying-Jiun J.; Vogt, Daniel; Wang, Yanling; Visel, Axel; Silberberg, Shanni N.; Nicholas, Cory R.; Danjo, Teruko; Pollack, Joshua L.; Pennacchio, Len A.; Anderson, Stewart; Sasai, Yoshiki; Baraban, Scott C.; Kriegstein, Arnold R.; Alvarez-Buylla, Arturo; Rubenstein, John L. R.

2013-01-01

The medial ganglionic eminence (MGE) is an embryonic forebrain structure that generates the majority of cortical interneurons. MGE transplantation into specific regions of the postnatal central nervous system modifies circuit function and improves deficits in mouse models of epilepsy, Parkinson's disease, pain, and phencyclidine-induced cognitive deficits. Herein, we describe approaches to generate MGE-like progenitor cells from mouse embryonic stem (ES) cells. Using a modified embryoid body method, we provided gene expression evidence that mouse ES-derived Lhx6+ cells closely resemble immature interneurons generated from authentic MGE-derived Lhx6+ cells. We hypothesized that enhancers that are active in the mouse MGE would be useful tools in detecting when ES cells differentiate into MGE cells. Here we demonstrate the utility of enhancer elements [422 (DlxI12b), Lhx6, 692, 1056, and 1538] as tools to mark MGE-like cells in ES cell differentiation experiments. We found that enhancers DlxI12b, 692, and 1538 are active in Lhx6-GFP+ cells, while enhancer 1056 is active in Olig2+ cells. These data demonstrate unique techniques to follow and purify MGE-like derivatives from ES cells, including GABAergic cortical interneurons and oligodendrocytes, for use in stem cell-based therapeutic assays and treatments. PMID:23658702

Comparative analysis of cadherin expression and connectivity patterns in the cerebellar system of ferret and mouse.

PubMed

Neudert, Franziska; Nuernberger, Krishna-K Monique; Redies, Christoph

2008-12-20

The cerebellum shows remarkable variations in the relative size of its divisions among vertebrate species. In the present study, we compare the cerebella of two mammals (ferret and mouse) by mapping the expression of three cadherins (cadherin-8, protocadherin-7, and protocadherin-10) at similar postnatal stages. The three cadherins are expressed differentially in parasagittal stripes in the cerebellar cortex, in the portions of the deep cerebellar nuclei, in the divisions of the inferior olivary nucleus, and in the lateral vestibular nucleus. The expression profiles suggest that the cadherin-positive structures are interconnected. The expression patterns resemble each other in ferret and mouse, although some differences can be observed. The general resemblance indicates that cerebellar organization is based on a common set of embryonic divisions in the two species. Consequently, the large differences in cerebellar morphology between the two species are more likely caused by differential growth of these embryonic divisions than by differences in early embryonic patterning. Based on the cadherin expression patterns, a model of corticonuclear projection territories in ferret and mouse is proposed. In summary, our results indicate that the cerebellar systems of rodents and carnivores display a relatively large degree of similarity in their molecular and functional organization.

Injurious effects of curcumin on maturation of mouse oocytes, fertilization and fetal development via apoptosis.

PubMed

Chen, Chia-Chi; Chan, Wen-Hsiung

2012-01-01

Curcumin, a common dietary pigment and spice, is a hydrophobic polyphenol derived from the rhizome of the herb Curcuma longa. Previously, we reported a cytotoxic effect of curcumin on mouse embryonic stem cells and blastocysts and its association with defects in subsequent development. In the present study, we further investigated the effects of curcumin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, curcumin induced a significant reduction in the rate of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with curcumin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments with an in vivo mouse model disclosed that consumption of drinking water containing 40 μM curcumin led to decreased oocyte maturation and in vitro fertilization as well as early embryonic developmental injury. Finally, pretreatment with a caspase-3-specific inhibitor effectively prevented curcumin-triggered injury effects, suggesting that embryo impairment by curcumin occurs mainly via a caspase-dependent apoptotic process.

Cloning and expression of sheep DNA methyltransferase 1 and its development-specific isoform.

PubMed

Taylor, Jane; Moore, Hannah; Beaujean, Nathalie; Gardner, John; Wilmut, Ian; Meehan, Richard; Young, Lorraine

2009-05-01

Unlike the mouse embryo, where loss of DNA methylation in the embryonic nucleus leaves cleavage stage embryos globally hypomethylated, sheep preimplantation embryos retain high levels of methylation until the blastocyst stage. We have cloned and sequenced sheep Dnmt1 and found it to be highly conserved with both the human and mouse homologues. Furthermore, we observed that the transcript normally expressed in adult somatic tissues is highly abundant in sheep oocytes. Throughout sheep preimplantation development the protein is retained in the cytoplasm whereas Dnmt1 transcript production declines after the embryonic genome activation at the 8-16 cell stage. Attempts to clone oocyte-specific 5' regions of Dnmt1, known to be present in the mouse and human gene, were unsuccessful. However, a novel ovine Dnmt1 exon, theoretically encoding 13 amino acids, was found to be expressed in sheep oocytes, preimplantation embryos and early fetal lineages, but not in the adult tissue. RNAi-mediated knockdown of this novel transcript resulted in embryonic developmental arrest at the late morula stage, suggesting an essential role for this isoform in sheep blastocyst formation. (c) 2008 Wiley-Liss, Inc.

I-SceI-mediated double-strand break does not increase the frequency of homologous recombination at the Dct locus in mouse embryonic stem cells.

PubMed

Fenina, Myriam; Simon-Chazottes, Dominique; Vandormael-Pournin, Sandrine; Soueid, Jihane; Langa, Francina; Cohen-Tannoudji, Michel; Bernard, Bruno A; Panthier, Jean-Jacques

2012-01-01

Targeted induction of double-strand breaks (DSBs) at natural endogenous loci was shown to increase the rate of gene replacement by homologous recombination in mouse embryonic stem cells. The gene encoding dopachrome tautomerase (Dct) is specifically expressed in melanocytes and their precursors. To construct a genetic tool allowing the replacement of Dct gene by any gene of interest, we generated an embryonic stem cell line carrying the recognition site for the yeast I-SceI meganuclease embedded in the Dct genomic segment. The embryonic stem cell line was electroporated with an I-SceI expression plasmid, and a template for the DSB-repair process that carried sequence homologies to the Dct target. The I-SceI meganuclease was indeed able to introduce a DSB at the Dct locus in live embryonic stem cells. However, the level of gene targeting was not improved by the DSB induction, indicating a limited capacity of I-SceI to mediate homologous recombination at the Dct locus. These data suggest that homologous recombination by meganuclease-induced DSB may be locus dependent in mammalian cells.

Generation of embryos directly from embryonic stem cells by tetraploid embryo complementation reveals a role for GATA factors in organogenesis.

PubMed

Duncan, S A

2005-12-01

Gene targeting in ES (embryonic stem) cells has been used extensively to study the role of proteins during embryonic development. In the traditional procedure, this requires the generation of chimaeric mice by introducing ES cells into blastocysts and allowing them to develop to term. Once chimaeric mice are produced, they are bred into a recipient mouse strain to establish germline transmission of the allele of interest. Although this approach has been used very successfully, the breeding cycles involved are time consuming. In addition, genes that are essential for organogenesis often have roles in the formation of extra-embryonic tissues that are essential for early stages of post-implantation development. For example, mice lacking the GATA transcription factors, GATA4 or GATA6, arrest during gastrulation due to an essential role for these factors in differentiation of extra-embryonic endoderm. This lethality has frustrated the study of these factors during the development of organs such as the liver and heart. Extraembryonic defects can, however, be circumvented by generating clonal mouse embryos directly from ES cells by tetraploid complementation. Here, we describe the usefulness and efficacy of this approach using GATA factors as an example.

LSD1 demethylase and the methyl-binding protein PHF20L1 prevent SET7 methyltransferase-dependent proteolysis of the stem-cell protein SOX2.

PubMed

Zhang, Chunxiao; Hoang, Nam; Leng, Feng; Saxena, Lovely; Lee, Logan; Alejo, Salvador; Qi, Dandan; Khal, Anthony; Sun, Hong; Lu, Fei; Zhang, Hui

2018-03-09

The pluripotency-controlling stem-cell protein SRY-box 2 (SOX2) plays a pivotal role in maintaining the self-renewal and pluripotency of embryonic stem cells and also of teratocarcinoma or embryonic carcinoma cells. SOX2 is monomethylated at lysine 119 (Lys-119) in mouse embryonic stem cells by the SET7 methyltransferase, and this methylation triggers ubiquitin-dependent SOX2 proteolysis. However, the molecular regulators and mechanisms controlling SET7-induced SOX2 proteolysis are unknown. Here, we report that in human ovarian teratocarcinoma PA-1 cells, methylation-dependent SOX2 proteolysis is dynamically regulated by the LSD1 lysine demethylase and a methyl-binding protein, PHD finger protein 20-like 1 (PHF20L1). We found that LSD1 not only removes the methyl group from monomethylated Lys-117 (equivalent to Lys-119 in mouse SOX2), but it also demethylates monomethylated Lys-42 in SOX2, a reaction that SET7 also regulated and that also triggered SOX2 proteolysis. Our studies further revealed that PHF20L1 binds both monomethylated Lys-42 and Lys-117 in SOX2 and thereby prevents SOX2 proteolysis. Down-regulation of either LSD1 or PHF20L1 promoted SOX2 proteolysis, which was prevented by SET7 inactivation in both PA-1 and mouse embryonic stem cells. Our studies also disclosed that LSD1 and PHF20L1 normally regulate the growth of pluripotent mouse embryonic stem cells and PA-1 cells by preventing methylation-dependent SOX2 proteolysis. In conclusion, our findings reveal an important mechanism by which the stability of the pluripotency-controlling stem-cell protein SOX2 is dynamically regulated by the activities of SET7, LSD1, and PHF20L1 in pluripotent stem cells. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Rhein Induces Oxidative Stress and Apoptosis in Mouse Blastocysts and Has Immunotoxic Effects during Embryonic Development.

PubMed

Huang, Chien-Hsun; Chan, Wen-Hsiung

2017-09-20

Rhein, a glucoside chemical compound found in a traditional Chinese medicine derived from the roots of rhubarb, induces cell apoptosis and is considered to have high potential as an antitumor drug. Several previous studies showed that rhein can inhibit cell proliferation and trigger mitochondria-related or endoplasmic reticulum (ER) stress-dependent apoptotic processes. However, the side effects of rhein on pre- and post-implantation embryonic development remain unclear. Here, we show that rhein has cytotoxic effects on blastocyst-stage mouse embryos and induces oxidative stress and immunotoxicity in mouse fetuses. Blastocysts incubated with 5-20 μM rhein showed significant cell apoptosis, as well as decreases in their inner cell mass cell numbers and total cell numbers. An in vitro development assay showed that rhein affected the developmental potentials of both pre- and post-implantation embryos. Incubation of blastocysts with 5-20 μM rhein was associated with increased resorption of post-implantation embryos and decreased fetal weight in an embryo transfer assay. Importantly, in an in vivo model, intravenous injection of dams with rhein (1, 3, and 5 mg/kg body weight/day) for four days resulted in apoptosis of blastocyst-stage embryos, early embryonic developmental injury, and decreased fetal weight. Intravenous injection of dams with 5 mg/kg body weight/day rhein significantly increased the total reactive oxygen species (ROS) content of fetuses and the transcription levels of antioxidant proteins in fetal livers. Additional work showed that rhein induced apoptosis through ROS generation, and that prevention of apoptotic processes effectively rescued the rhein-induced injury effects on embryonic development. Finally, the transcription levels of the innate-immunity related genes, CXCL1 , IL-1 β and IL-8 , were down-regulated in the fetuses of dams that received intravenous injections of rhein. These results collectively show that rhein has the potential to induce embryonic cytotoxicity and induce oxidative stress and immunotoxicity during the development of mouse embryos.

Derivation, propagation and differentiation of human embryonic stem cells.

PubMed

Conley, Brock J; Young, Julia C; Trounson, Alan O; Mollard, Richard

2004-04-01

Embryonic stem (ES) cells are in vitro cultivated pluripotent cells derived from the inner cell mass (ICM) of the embryonic blastocyst. Attesting to their pluripotency, ES cells can be differentiated into representative derivatives of all three embryonic germ layers (endoderm, ectoderm and mesoderm) both in vitro and in vivo. Although mouse ES cells have been studied for many years, human ES cells have only more recently been derived and successfully propagated. Many biochemical differences and culture requirements between mouse and human ES cells have been described, yet despite these differences the study of murine ES cells has provided important insights into methodologies aimed at generating a greater and more in depth understanding of human ES cell biology. One common feature of both mouse and human ES cells is their capacity to undergo controlled differentiation into spheroid structures termed embryoid bodies (EBs). EBs recapitulate several aspects of early development, displaying regional-specific differentiation programs into derivatives of all three embryonic germ layers. For this reason, EB formation has been utilised as an initial step in a wide range of studies aimed at differentiating both mouse and human ES cells into a specific and desired cell type. Recent reports utilising specific growth factor combinations and cell-cell induction systems have provided alternative strategies for the directed differentiation of cells into a desired lineage. According to each one of these strategies, however, a relatively high cell lineage heterogeneity remains, necessitating subsequent purification steps including mechanical dissection, selective media or fluorescent or magnetic activated cell sorting (FACS and MACS, respectively). In the future, the ability to specifically direct differentiation of human ES cells at 100% efficiency into a desired lineage will allow us to fully explore the potential of these cells in the analysis of early human development, drug discovery, drug testing and repair of damaged or diseased tissues via transplantation.

Mouse embryonic stem cells, but not somatic cells, predominantly use homologous recombination to repair double-strand DNA breaks.

PubMed

Tichy, Elisia D; Pillai, Resmi; Deng, Li; Liang, Li; Tischfield, Jay; Schwemberger, Sandy J; Babcock, George F; Stambrook, Peter J

2010-11-01

Embryonic stem (ES) cells give rise to all cell types of an organism. Since mutations at this embryonic stage would affect all cells and be detrimental to the overall health of an organism, robust mechanisms must exist to ensure that genomic integrity is maintained. To test this proposition, we compared the capacity of murine ES cells to repair DNA double-strand breaks with that of differentiated cells. Of the 2 major pathways that repair double-strand breaks, error-prone nonhomologous end joining (NHEJ) predominated in mouse embryonic fibroblasts, whereas the high fidelity homologous recombinational repair (HRR) predominated in ES cells. Microhomology-mediated end joining, an emerging repair pathway, persisted at low levels in all cell types examined. The levels of proteins involved in HRR and microhomology-mediated end joining were highly elevated in ES cells compared with mouse embryonic fibroblasts, whereas those for NHEJ were quite variable, with DNA Ligase IV expression low in ES cells. The half-life of DNA Ligase IV protein was also low in ES cells. Attempts to increase the abundance of DNA Ligase IV protein by overexpression or inhibition of its degradation, and thereby elevate NHEJ in ES cells, were unsuccessful. When ES cells were induced to differentiate, however, the level of DNA Ligase IV protein increased, as did the capacity to repair by NHEJ. The data suggest that preferential use of HRR rather than NHEJ may lend ES cells an additional layer of genomic protection and that the limited levels of DNA Ligase IV may account for the low level of NHEJ activity.

Localization of Brachyury (T) in embryonic and extraembryonic tissues during mouse gastrulation.

PubMed

Inman, Kimberly E; Downs, Karen M

2006-10-01

T-box gene family members have important roles during murine embryogenesis, gastrulation, and organogenesis. Although relatively little is known about how T-box genes are regulated, published gene expression studies have revealed dynamic and specific patterns in both embryonic and extraembryonic tissues of the mouse conceptus. Mutant alleles of the T-box gene Brachyury (T) have identified roles in formation of mesoderm and its derivatives, such as somites and the allantois. However, given the cell autonomous nature of T gene activity and conflicting results of gene expression studies, it has been difficult to attribute a primary function to T in normal allantoic development. We report localization of T protein by sectional immunohistochemistry in both embryonic and extraembryonic tissues during mouse gastrulation, emphasizing T localization within the allantois. T was detected in all previously reported sites within the conceptus, including the primitive streak and its derivatives, nascent embryonic mesoderm, the node and notochord, as well as notochord-associated endoderm and posterior neurectoderm. In addition, we have clarified T within the allantois, where it was first detected in the proximal midline of the late allantoic bud (approximately 7.5 days postcoitum, dpc) and persisted within an expanded midline domain until 6-somite pairs (s; approximately 8.5 dpc). Lastly, we have discovered several novel T sites, including the developing heart, visceral endoderm, extraembryonic ectoderm, and its derivative, chorionic ectoderm. Together, these data provide a unified picture of T in the mammalian conceptus, and demonstrate T's presence in unrelated cell types and tissues in highly dynamic spatiotemporal patterns in both embryonic and extraembryonic tissues.

Endothelin-1 signalling controls early embryonic heart rate in vitro and in vivo.

PubMed

Karppinen, S; Rapila, R; Mäkikallio, K; Hänninen, S L; Rysä, J; Vuolteenaho, O; Tavi, P

2014-02-01

Spontaneous activity of embryonic cardiomyocytes originates from sarcoplasmic reticulum (SR) Ca(2+) release during early cardiogenesis. However, the regulation of heart rate during embryonic development is still not clear. The aim of this study was to determine how endothelin-1 (ET-1) affects the heart rate of embryonic mice, as well as the pathway through which it exerts its effects. The effects of ET-1 and ET-1 receptor inhibition on cardiac contraction were studied using confocal Ca(2+) imaging of isolated mouse embryonic ventricular cardiomyocytes and ultrasonographic examination of embryonic cardiac contractions in utero. In addition, the amount of ET-1 peptide and ET receptor a (ETa) and b (ETb) mRNA levels were measured during different stages of development of the cardiac muscle. High ET-1 concentration and expression of both ETa and ETb receptors was observed in early cardiac tissue. ET-1 was found to increase the frequency of spontaneous Ca(2+) oscillations in E10.5 embryonic cardiomyocytes in vitro. Non-specific inhibition of ET receptors with tezosentan caused arrhythmia and bradycardia in isolated embryonic cardiomyocytes and in whole embryonic hearts both in vitro (E10.5) and in utero (E12.5). ET-1-mediated stimulation of early heart rate was found to occur via ETb receptors and subsequent inositol trisphosphate receptor activation and increased SR Ca(2+) leak. Endothelin-1 is required to maintain a sufficient heart rate, as well as to prevent arrhythmia during early development of the mouse heart. This is achieved through ETb receptor, which stimulates Ca(2+) leak through IP3 receptors. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Identification and Characterization of Long Non-Coding RNAs Related to Mouse Embryonic Brain Development from Available Transcriptomic Data

PubMed Central

He, Hongjuan; Xiu, Youcheng; Guo, Jing; Liu, Hui; Liu, Qi; Zeng, Tiebo; Chen, Yan; Zhang, Yan; Wu, Qiong

2013-01-01

Long non-coding RNAs (lncRNAs) as a key group of non-coding RNAs have gained widely attention. Though lncRNAs have been functionally annotated and systematic explored in higher mammals, few are under systematical identification and annotation. Owing to the expression specificity, known lncRNAs expressed in embryonic brain tissues remain still limited. Considering a large number of lncRNAs are only transcribed in brain tissues, studies of lncRNAs in developmental brain are therefore of special interest. Here, publicly available RNA-sequencing (RNA-seq) data in embryonic brain are integrated to identify thousands of embryonic brain lncRNAs by a customized pipeline. A significant proportion of novel transcripts have not been annotated by available genomic resources. The putative embryonic brain lncRNAs are shorter in length, less spliced and show less conservation than known genes. The expression of putative lncRNAs is in one tenth on average of known coding genes, while comparable with known lncRNAs. From chromatin data, putative embryonic brain lncRNAs are associated with active chromatin marks, comparable with known lncRNAs. Embryonic brain expressed lncRNAs are also indicated to have expression though not evident in adult brain. Gene Ontology analysis of putative embryonic brain lncRNAs suggests that they are associated with brain development. The putative lncRNAs are shown to be related to possible cis-regulatory roles in imprinting even themselves are deemed to be imprinted lncRNAs. Re-analysis of one knockdown data suggests that four regulators are associated with lncRNAs. Taken together, the identification and systematic analysis of putative lncRNAs would provide novel insights into uncharacterized mouse non-coding regions and the relationships with mammalian embryonic brain development. PMID:23967161

Reprogramming primordial germ cells (PGC) to embryonic germ (EG) cells.

PubMed

Durcova-Hills, Gabriela; Surani, Azim

2008-04-01

In this unit we describe the derivation of pluripotent embryonic germ (EG) cells from mouse primordial germ cells (PGCs) isolated from both 8.5- and 11.5-days post-coitum (dpc) embryos. Once EG cells are derived we explain how to propagate and characterize the cell lines. We introduce readers to PGCs and explain differences between PGCs and their in vitro derivatives EG cells. Finally, we also compare mouse EG cells with ES cells. This unit will be of great interest to anyone interested in PGCs or studying the behavior of cultured PGCs or the derivation of new EG cell lines.

Data on the potential impact of food supplements on the growth of mouse embryonic stem cells.

PubMed

Correia, Marcelo; Sousa, Maria I; Rodrigues, Ana S; Perestrelo, Tânia; Pereira, Sandro L; Ribeiro, Marcelo F; Ramalho-Santos, João

2016-06-01

The use of new compounds as dietary supplements is increasing, but little is known in terms of possible consequences of their use. Pluripotent stem cells are a promising research tool for citotoxicological research for evaluation of proliferation, cell death, pluripotency and differentiation. Using the mouse embryonic stem cell (mESC) model, we present data on three different compounds that have been proposed as new potential supplements for co-adjuvant disease treatments: kaempferol, berberine and Tauroursodeoxycholic acid (TUDCA). Cell number and viability were monitored following treatment with increased concentrations of each drug in pluripotent culture conditions.

The Application of a Chemical Determination of N-Homocysteinylation Levels in Developing Mouse Embryos: Implication for Folate Responsive Birth Defects

PubMed Central

Fathe, Kristin; Person, Maria D.; Finnell, Richard H.

2014-01-01

Elevated homocysteine levels have long been associated with various disease states, including cardiovascular disease and birth defects, including neural tube defects (NTDs). One hypothesis regarding the strong correlation between these various disorders and high levels of homocysteine is that a reactive form of this small molecule can attach to mammalian proteins in a phenomenon known as homocysteinylation. These posttranslational modifications may become antigenic, or may even directly disrupt certain protein function. It remains to be determined whether dietary influences that can cause globally increased levels of circulating homocysteine confer negative effects maternally, or may otherwise negatively and materially impact the metabolic balance in developing embryos. Herein we present the application of a chemical method of determination of N-homocysteinylation to a set of neural tube closure stage mouse embryos and their mothers. We explore the uses of this newly-described technique to investigate levels of maternal and embryonic N-homocysteinylation using dietary manipulations of onecarbon metabolism with two known folate responsive neural tube defect mouse models. The data presented reveals that although diet appeared to have significant effects on the maternal metabolic status, those effects did not directly correlate to the embryonic folate or N-homocysteinylation status. Our studies indicate that maternal diet and embryonic genotype most significantly affected the embryonic developmental outcome. PMID:25620692

Generation and gene expression profiling of 48 transcription-factor-inducible mouse embryonic stem cell lines.

PubMed

Yamamizu, Kohei; Sharov, Alexei A; Piao, Yulan; Amano, Misa; Yu, Hong; Nishiyama, Akira; Dudekula, Dawood B; Schlessinger, David; Ko, Minoru S H

2016-05-06

Mouse embryonic stem cells (ESCs) can differentiate into a wide range - and possibly all cell types in vitro, and thus provide an ideal platform to study systematically the action of transcription factors (TFs) in cell differentiation. Previously, we have generated and analyzed 137 TF-inducible mouse ESC lines. As an extension of this "NIA Mouse ESC Bank," we generated and characterized 48 additional mouse ESC lines, in which single TFs in each line could be induced in a doxycycline-controllable manner. Together, with the previous ESC lines, the bank now comprises 185 TF-manipulable ESC lines (>10% of all mouse TFs). Global gene expression (transcriptome) profiling revealed that the induction of individual TFs in mouse ESCs for 48 hours shifts their transcriptomes toward specific differentiation fates (e.g., neural lineages by Myt1 Isl1, and St18; mesodermal lineages by Pitx1, Pitx2, Barhl2, and Lmx1a; white blood cells by Myb, Etv2, and Tbx6, and ovary by Pitx1, Pitx2, and Dmrtc2). These data also provide and lists of inferred target genes of each TF and possible functions of these TFs. The results demonstrate the utility of mouse ESC lines and their transcriptome data for understanding the mechanism of cell differentiation and the function of TFs.

Impaired cardiac energy metabolism in embryos lacking adrenergic stimulation

PubMed Central

Baker, Candice N.; Gidus, Sarah A.; Price, George F.; Peoples, Jessica N. R.

2014-01-01

As development proceeds from the embryonic to fetal stages, cardiac energy demands increase substantially, and oxidative phosphorylation of ADP to ATP in mitochondria becomes vital. Relatively little, however, is known about the signaling mechanisms regulating the transition from anaerobic to aerobic metabolism that occurs during the embryonic period. The main objective of this study was to test the hypothesis that adrenergic hormones provide critical stimulation of energy metabolism during embryonic/fetal development. We examined ATP and ADP concentrations in mouse embryos lacking adrenergic hormones due to targeted disruption of the essential dopamine β-hydroxylase (Dbh) gene. Embryonic ATP concentrations decreased dramatically, whereas ADP concentrations rose such that the ATP/ADP ratio in the adrenergic-deficient group was nearly 50-fold less than that found in littermate controls by embryonic day 11.5. We also found that cardiac extracellular acidification and oxygen consumption rates were significantly decreased, and mitochondria were significantly larger and more branched in adrenergic-deficient hearts. Notably, however, the mitochondria were intact with well-formed cristae, and there was no significant difference observed in mitochondrial membrane potential. Maternal administration of the adrenergic receptor agonists isoproterenol or l-phenylephrine significantly ameliorated the decreases in ATP observed in Dbh−/− embryos, suggesting that α- and β-adrenergic receptors were effective modulators of ATP concentrations in mouse embryos in vivo. These data demonstrate that adrenergic hormones stimulate cardiac energy metabolism during a critical period of embryonic development. PMID:25516547

Sertad1 encodes a novel transcriptional co-activator of SMAD1 in mouse embryonic hearts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Yin; Zhao, Shaomin; School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069

2013-11-29

Highlights: •SERTAD1 interacts with SMAD1. •Sertad1 is expressed in mouse embryonic hearts. •SERTAD1 is localized in both cytoplasm and nucleus of cardiomyocytes. •SERTAD1 enhances expression of BMP target cardiogenic genes as a SMAD1 co-activator. -- Abstract: Despite considerable advances in surgical repairing procedures, congenital heart diseases (CHDs) remain the leading noninfectious cause of infant morbidity and mortality. Understanding the molecular/genetic mechanisms underlying normal cardiogenesis will provide essential information for the development of novel diagnostic and therapeutic strategies against CHDs. BMP signaling plays complex roles in multiple cardiogenic processes in mammals. SMAD1 is a canonical nuclear mediator of BMP signaling, themore » activity of which is critically regulated through its interaction partners. We screened a mouse embryonic heart yeast two-hybrid library using Smad1 as bait and identified SERTAD1 as a novel interaction partner of SMAD1. SERTAD1 contains multiple potential functional domains, including two partially overlapping transactivation domains at the C terminus. The SERTAD1-SMAD1 interaction in vitro and in mammalian cells was further confirmed through biochemical assays. The expression of Sertad1 in developing hearts was demonstrated using RT-PCR, western blotting and in situ hybridization analyses. We also showed that SERTAD1 was localized in both the cytoplasm and nucleus of immortalized cardiomyocytes and primary embryonic cardiomyocyte cultures. The overexpression of SERTAD1 in cardiomyocytes not only enhanced the activity of two BMP reporters in a dose-dependent manner but also increased the expression of several known BMP/SMAD regulatory targets. Therefore, these data suggest that SERTAD1 acts as a SMAD1 transcriptional co-activator to promote the expression of BMP target genes during mouse cardiogenesis.« less

Mouse oocytes nucleoli rescue embryonic development of porcine enucleolated oocytes.

PubMed

Morovic, Martin; Strejcek, Frantisek; Nakagawa, Shoma; Deshmukh, Rahul S; Murin, Matej; Benc, Michal; Fulka, Helena; Kyogoku, Hirohisa; Pendovski, Lazo; Fulka, Josef; Laurincik, Jozef

2017-12-01

It is well known that nucleoli of fully grown mammalian oocytes are indispensable for embryonic development. Therefore, the embryos originated from previously enucleolated (ENL) oocytes undergo only one or two cleavages and then their development ceases. In our study the interspecies (mouse/pig) nucleolus transferred embryos (NuTE) were produced and their embryonic development was analyzed by autoradiography, transmission electron microscopy (TEM) and immunofluorescence (C23 and upstream binding factor (UBF)). Our results show that the re-injection of isolated oocyte nucleoli, either from the pig (P + P) or mouse (P + M), into previously enucleolated and subsequently matured porcine oocytes rescues their development after parthenogenetic activation and some of these develop up to the blastocyst stage (P + P, 11.8%; P + M, 13.5%). In nucleolus re-injected 8-cell and blastocyst stage embryos the number of nucleoli labeled with C23 in P + P and P + M groups was lower than in control (non-manipulated) group. UBF was localized in small foci within the nucleoli of blastocysts in control and P + P embryos, however, in P + M embryos the labeling was evenly distributed in the nucleoplasm. The TEM and autoradiographic evaluations showed the formation of functional nucleoli and de novo rRNA synthesis at the 8-cell stage in both, control and P + P group. In the P + M group the formation of comparable nucleoli was delayed. In conclusion, our results indicate that the mouse nucleolus can rescue embryonic development of enucleolated porcine oocytes, but the localization of selected nucleolar proteins, the timing of transcription activation and the formation of the functional nucleoli in NuTE compared with control group show evident aberrations.

Dual effects of fluoxetine on mouse early embryonic development.

PubMed

Kim, Chang-Woon; Choe, Changyong; Kim, Eun-Jin; Lee, Jae-Ik; Yoon, Sook-Young; Cho, Young-Woo; Han, Sunkyu; Tak, Hyun-Min; Han, Jaehee; Kang, Dawon

2012-11-15

Fluoxetine, a selective serotonin reuptake inhibitor, regulates a variety of physiological processes, such as cell proliferation and apoptosis, in mammalian cells. Little is known about the role of fluoxetine in early embryonic development. This study was undertaken to investigate the effect of fluoxetine during mouse early embryonic development. Late two-cell stage embryos (2-cells) were cultured in the presence of various concentrations of fluoxetine (1 to 50μM) for different durations. When late 2-cells were incubated with 5μM fluoxetine for 6h, the percentage that developed into blastocysts increased compared to the control value. However, late 2-cells exposed to fluoxetine (5μM) over 24h showed a reduction in blastocyst formation. The addition of fluoxetine (5μM) together with KN93 or KN62 (calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitors) failed to increase blastocyst formation. Fluoxetine treatment inhibited TREK-1 and TREK-2, members of the two-pore domain K(+) channel family expressed in mouse embryos, activities, indicating that fluoxetine-induced membrane depolarization in late 2-cells might have resulted from TREK inhibition. In addition, long-term exposure to fluoxetine altered the TREK mRNA expression levels. Furthermore, injection of siRNA targeting TREKs significantly decreased blastocyst formation by ~30% compared to injection of scrambled siRNA. Long-term exposure of fluoxetine had no effect on blastocyst formation of TREK deficient embryos. These results indicate that low-dose and short-term exposures of late 2-cells to fluoxetine probably increase blastocyst formation through activation of CaMKII-dependent signal transduction pathways, whereas long-term exposure decreases mouse early embryonic development through inhibition of TREK channel gating. Copyright © 2012 Elsevier Inc. All rights reserved.

Dual effects of fluoxetine on mouse early embryonic development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Chang-Woon; Department of Obstetrics and Gynecology, Samsung Changwon Hospital, Sungkyunkwan University, Changwon 630-723; Choe, Changyong

2012-11-15

Fluoxetine, a selective serotonin reuptake inhibitor, regulates a variety of physiological processes, such as cell proliferation and apoptosis, in mammalian cells. Little is known about the role of fluoxetine in early embryonic development. This study was undertaken to investigate the effect of fluoxetine during mouse early embryonic development. Late two-cell stage embryos (2-cells) were cultured in the presence of various concentrations of fluoxetine (1 to 50 μM) for different durations. When late 2-cells were incubated with 5 μM fluoxetine for 6 h, the percentage that developed into blastocysts increased compared to the control value. However, late 2-cells exposed to fluoxetinemore » (5 μM) over 24 h showed a reduction in blastocyst formation. The addition of fluoxetine (5 μM) together with KN93 or KN62 (calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitors) failed to increase blastocyst formation. Fluoxetine treatment inhibited TREK-1 and TREK-2, members of the two-pore domain K{sup +} channel family expressed in mouse embryos, activities, indicating that fluoxetine-induced membrane depolarization in late 2-cells might have resulted from TREK inhibition. In addition, long-term exposure to fluoxetine altered the TREK mRNA expression levels. Furthermore, injection of siRNA targeting TREKs significantly decreased blastocyst formation by ∼ 30% compared to injection of scrambled siRNA. Long-term exposure of fluoxetine had no effect on blastocyst formation of TREK deficient embryos. These results indicate that low-dose and short-term exposures of late 2-cells to fluoxetine probably increase blastocyst formation through activation of CaMKII-dependent signal transduction pathways, whereas long-term exposure decreases mouse early embryonic development through inhibition of TREK channel gating. Highlights: ► Short-term exposure of 2-cells to fluoxetine enhances mouse blastocyst formation. ► The enhancive effect of fluoxetine is resulted from CaMKII activation. ► Long-term exposure of 2-cells to fluoxetine decreases mouse blastocyst formation. ► The inhibitory effect of fluoxetine is mediated through TREK channel gating.« less

Evaluation of a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay (SOT)

EPA Science Inventory

The Embryonic Stem Cell Test (EST) has been used to evaluate the effects of xenobiotics using three endpoints, stem cell differentiation, stem cell viability and 3T3-cell viability. Our research goal is to establish amodel system that would evaluate chemical effects using a singl...

Optimization of a serum-free culture medium for mouse embryonic stem cells using design of experiments (DoE) methodology.

PubMed

Knöspel, Fanny; Schindler, Rudolf K; Lübberstedt, Marc; Petzolt, Stephanie; Gerlach, Jörg C; Zeilinger, Katrin

2010-12-01

The in vitro culture behaviour of embryonic stem cells (ESC) is strongly influenced by the culture conditions. Current culture media for expansion of ESC contain some undefined substances. Considering potential clinical translation work with such cells, the use of defined media is desirable. We have used Design of Experiments (DoE) methods to investigate the composition of a serum-free chemically defined culture medium for expansion of mouse embryonic stem cells (mESC). Factor screening analysis according to Plackett-Burman revealed that insulin and leukaemia inhibitory factor (LIF) had a significant positive influence on the proliferation activity of the cells, while zinc and L: -cysteine reduced the cell growth. Further analysis using minimum run resolution IV (MinRes IV) design indicates that following factor adjustment LIF becomes the main factor for the survival and proliferation of mESC. In conclusion, DoE screening assays are applicable to develop and to refine culture media for stem cells and could also be employed to optimize culture media for human embryonic stem cells (hESC).

Fluorescence-based visualization of autophagic activity predicts mouse embryo viability

NASA Astrophysics Data System (ADS)

Tsukamoto, Satoshi; Hara, Taichi; Yamamoto, Atsushi; Kito, Seiji; Minami, Naojiro; Kubota, Toshiro; Sato, Ken; Kokubo, Toshiaki

2014-03-01

Embryo quality is a critical parameter in assisted reproductive technologies. Although embryo quality can be evaluated morphologically, embryo morphology does not correlate perfectly with embryo viability. To improve this, it is important to understand which molecular mechanisms are involved in embryo quality control. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic materials sequestered by autophagosomes are degraded in lysosomes. We previously demonstrated that autophagy is highly activated after fertilization and is essential for further embryonic development. Here, we developed a simple fluorescence-based method for visualizing autophagic activity in live mouse embryos. Our method is based on imaging of the fluorescence intensity of GFP-LC3, a versatile marker for autophagy, which is microinjected into the embryos. Using this method, we show that embryonic autophagic activity declines with advancing maternal age, probably due to a decline in the activity of lysosomal hydrolases. We also demonstrate that embryonic autophagic activity is associated with the developmental viability of the embryo. Our results suggest that embryonic autophagic activity can be utilized as a novel indicator of embryo quality.

Femtosecond laser assisted photo-transfection and differentiation of mouse embryonic stem cells

NASA Astrophysics Data System (ADS)

Thobakgale, Lebogang; Manoto, Sello; Ombinda Lemboumba, Satuurnin; Maaza, Malik; Mthunzi-Kufa, Patience

2018-02-01

In tissue engineering research, stem cells have been used as starting material in the synthesis of mammalian cells for the treatment of various cell based diseases. This is done by manipulating the DNA content of the cells to induce a specific effect such as increased proliferation or developing a new cell type through the process of differentiation. Such controlled gene expression of stem cells is achieved by the method of transfection, where exogenous plasmid deoxyribonucleic acid (pDNA) is inserted into a stem cell using chemical, viral or physical methods. In this research, we used femtosecond (fs) laser pulses from a home-build microscope system to perforate the cellular membrane and allow entry of selected pDNA to alter the behaviour of mouse embryonic stem cells (mESCs). In one set of experiments, we induce fluorescence on mESCs using green fluorescence protein plasmid (pGFP) while in other tests; differentiation of mESCs into endoderm cells is performed using Sox-17 plasmid DNA (pSox-17). Primitive endoderm formation was thereafter confirmed using polymerase chain reactions (PCR) and the Sox-17 primer. Cell viability studies using adenosine triphosphate were also conducted. From the data, it was concluded that the photo-transfection method is biocompatible since it was able to induce fluorescence in mESCs. Secondly, it was confirmed that Sox-17 was photo-transfected successfully using 6 μW laser power, 128 fs pulses and 1kHz pulse repetition rate.

Human embryonic lung epithelial tips are multipotent progenitors that can be expanded in vitro as long-term self-renewing organoids

PubMed Central

Nikolić, Marko Z; Caritg, Oriol; Jeng, Quitz; Johnson, Jo-Anne; Sun, Dawei; Howell, Kate J; Brady, Jane L; Laresgoiti, Usua; Allen, George; Butler, Richard; Zilbauer, Matthias; Giangreco, Adam; Rawlins, Emma L

2017-01-01

The embryonic mouse lung is a widely used substitute for human lung development. For example, attempts to differentiate human pluripotent stem cells to lung epithelium rely on passing through progenitor states that have only been described in mouse. The tip epithelium of the branching mouse lung is a multipotent progenitor pool that self-renews and produces differentiating descendants. We hypothesized that the human distal tip epithelium is an analogous progenitor population and tested this by examining morphology, gene expression and in vitro self-renewal and differentiation capacity of human tips. These experiments confirm that human and mouse tips are analogous and identify signalling pathways that are sufficient for long-term self-renewal of human tips as differentiation-competent organoids. Moreover, we identify mouse-human differences, including markers that define progenitor states and signalling requirements for long-term self-renewal. Our organoid system provides a genetically-tractable tool that will allow these human-specific features of lung development to be investigated. DOI: http://dx.doi.org/10.7554/eLife.26575.001 PMID:28665271

Cellular origin of fibronectin in interspecies hybrid kidneys

PubMed Central

1984-01-01

The cellular origin of fibronectin in the kidney was studied in three experimental models. Immunohistochemical techniques that use cross- reacting or species-specific antibodies against mouse or chicken fibronectin were employed. In the first model studied, initially avascular mouse kidneys cultured on avian chorioallantoic membranes differentiate into epithelial kidney tubules and become vascularized by chorioallantoic vessels. Subsequently, hybrid glomeruli composed of mouse podocytes and avian endothelial-mesangial cells form. In immunohistochemical studies, cross-reacting antibodies to fibronectin stained vascular walls, tubular basement membranes, interstitium, and glomeruli of mouse kidney grafts. The species-specific antibodies reacting only with mouse fibronectin stained interstitial areas and tubular basement membranes, but showed no reaction with hybrid glomeruli and avian vascular walls. In contrast, species-specific antibodies against chicken fibronectin stained both the interstitial areas and the vascular walls as well as the endothelial-mesangial areas of the hybrid glomeruli, but did not stain the mouse-derived epithelial structures of the kidneys. In the second model, embryonic kidneys cultured under avascular conditions in vitro develop glomerular tufts, which are devoid of endothelial cells. These explants showed fluorescence staining for fibronectin only in tubular basement membranes and in interstitium. The avascular, purely epithelial glomerular bodies remained unstained. Finally, in outgrowths of separated embryonic glomeruli, the cross-reacting fibronectin antibodies revealed two populations of cells: one devoid of fibronectin and another expressing fibronectin in strong fibrillar and granular patterns. These results favor the idea that the main endogenous cellular sources for fibronectin in the embryonic kidney are the interstitial and vascular cells. All experiments presented here suggest that fibronectin is not synthesized by glomerular epithelial cells in vivo. PMID:6389571

Optical coherence tomography guided microinjections in live mouse embryos: high-resolution targeted manipulation for mouse embryonic research.

PubMed

Syed, Saba H; Coughlin, Andrew J; Garcia, Monica D; Wang, Shang; West, Jennifer L; Larin, Kirill V; Larina, Irina V

2015-05-01

The ability to conduct highly localized delivery of contrast agents, viral vectors, therapeutic or pharmacological agents, and signaling molecules or dyes to live mammalian embryos is greatly desired to enable a variety of studies in the field of developmental biology, such as investigating the molecular regulation of cardiovascular morphogenesis. To meet such a demand, we introduce, for the first time, the concept of employing optical coherence tomography (OCT)-guide microinjections in live mouse embryos, which provides precisely targeted manipulation with spatial resolution at the micrometer scale. The feasibility demonstration is performed with experimental studies on cultured live mouse embryos at E8.5 and E9.5. Additionally, we investigate the OCT-guided microinjection of gold–silica nanoshells to the yolk sac vasculature of live cultured mouse embryos at the stage when the heart just starts to beat, as a potential approach for dynamic assessment of cardiovascular form and function before the onset of blood cell circulation. Also, the capability of OCT to quantitatively monitor and measure injection volume is presented. Our results indicate that OCT-guided microinjection could be a useful tool for mouse embryonic research.

Optical coherence tomography guided microinjections in live mouse embryos: high-resolution targeted manipulation for mouse embryonic research

PubMed Central

Syed, Saba H.; Coughlin, Andrew J.; Garcia, Monica D.; Wang, Shang; West, Jennifer L.; Larin, Kirill V.; Larina, Irina V.

2015-01-01

Abstract. The ability to conduct highly localized delivery of contrast agents, viral vectors, therapeutic or pharmacological agents, and signaling molecules or dyes to live mammalian embryos is greatly desired to enable a variety of studies in the field of developmental biology, such as investigating the molecular regulation of cardiovascular morphogenesis. To meet such a demand, we introduce, for the first time, the concept of employing optical coherence tomography (OCT)-guide microinjections in live mouse embryos, which provides precisely targeted manipulation with spatial resolution at the micrometer scale. The feasibility demonstration is performed with experimental studies on cultured live mouse embryos at E8.5 and E9.5. Additionally, we investigate the OCT-guided microinjection of gold–silica nanoshells to the yolk sac vasculature of live cultured mouse embryos at the stage when the heart just starts to beat, as a potential approach for dynamic assessment of cardiovascular form and function before the onset of blood cell circulation. Also, the capability of OCT to quantitatively monitor and measure injection volume is presented. Our results indicate that OCT-guided microinjection could be a useful tool for mouse embryonic research. PMID:25581495

Lack of centrioles and primary cilia in STIL−/− mouse embryos

PubMed Central

David, Ahuvit; Liu, Fengying; Tibelius, Alexandra; Vulprecht, Julia; Wald, Diana; Rothermel, Ulrike; Ohana, Reut; Seitel, Alexander; Metzger, Jasmin; Ashery-Padan, Ruth; Meinzer, Hans-Peter; Gröne, Hermann-Josef; Izraeli, Shai; Krämer, Alwin

2014-01-01

Although most animal cells contain centrosomes, consisting of a pair of centrioles, their precise contribution to cell division and embryonic development is unclear. Genetic ablation of STIL, an essential component of the centriole replication machinery in mammalian cells, causes embryonic lethality in mice around mid gestation associated with defective Hedgehog signaling. Here, we describe, by focused ion beam scanning electron microscopy, that STIL−/− mouse embryos do not contain centrioles or primary cilia, suggesting that these organelles are not essential for mammalian development until mid gestation. We further show that the lack of primary cilia explains the absence of Hedgehog signaling in STIL−/− cells. Exogenous re-expression of STIL or STIL microcephaly mutants compatible with human survival, induced non-templated, de novo generation of centrioles in STIL−/− cells. Thus, while the abscence of centrioles is compatible with mammalian gastrulation, lack of centrioles and primary cilia impairs Hedgehog signaling and further embryonic development. PMID:25486474

Lack of centrioles and primary cilia in STIL(-/-) mouse embryos.

PubMed

David, Ahuvit; Liu, Fengying; Tibelius, Alexandra; Vulprecht, Julia; Wald, Diana; Rothermel, Ulrike; Ohana, Reut; Seitel, Alexander; Metzger, Jasmin; Ashery-Padan, Ruth; Meinzer, Hans-Peter; Gröne, Hermann-Josef; Izraeli, Shai; Krämer, Alwin

2014-01-01

Although most animal cells contain centrosomes, consisting of a pair of centrioles, their precise contribution to cell division and embryonic development is unclear. Genetic ablation of STIL, an essential component of the centriole replication machinery in mammalian cells, causes embryonic lethality in mice around mid gestation associated with defective Hedgehog signaling. Here, we describe, by focused ion beam scanning electron microscopy, that STIL(-/-) mouse embryos do not contain centrioles or primary cilia, suggesting that these organelles are not essential for mammalian development until mid gestation. We further show that the lack of primary cilia explains the absence of Hedgehog signaling in STIL(-/-) cells. Exogenous re-expression of STIL or STIL microcephaly mutants compatible with human survival, induced non-templated, de novo generation of centrioles in STIL(-/-) cells. Thus, while the abscence of centrioles is compatible with mammalian gastrulation, lack of centrioles and primary cilia impairs Hedgehog signaling and further embryonic development.

Formation of gut-like structures in vitro from mouse embryonic stem cells.

PubMed

Torihashi, Shigeko

2006-01-01

Embryonic stem (ES) cells have the potential to differentiate into all cell types originating from the three germ layers; however, there are still few reports about the formation of functional organs from embryonic stem cells. Recently, we reported that by hanging drops of mouse ES cells, embryoid bodies (EBs) formed gut-like structures in vitro composed of three layers corresponding to the epithelium, lamina propria, and musculature. The morphological features and the process of formation are similar to gut and its organogenesis in vivo. Thus, this is a good model for development of the gut and a useful tool for analysis of the factors required for gut organogenesis. The protocol basically involves a method of hanging drops to make EBs, which are then plated on coated dishes for outgrowth. EBs develop to form gut-like structures when induced to spontaneously enter a program of differentiation in vitro without addition of any extrinsic factors.

PI3K/Akt-dependent functions of TFII-I transcription factors in mouse embryonic stem cells.

PubMed

Chimge, Nyam-Osor; Makeyev, Aleksandr V; Waigel, Sabine J; Enkhmandakh, Badam; Bayarsaihan, Dashzeveg

2012-04-01

Activation of PI3K/Akt signaling is sufficient to maintain the pluripotency of mouse embryonic stem cells (mESC) and results in down-regulation of Gtf2i and Gtf2ird1 encoding TFII-I family transcription factors. To investigate how these genes might be involved in the process of embryonic stem cell differentiation, we performed expression microarray profiling of mESC upon inhibition of PI3K by LY294002. This analysis revealed significant alterations in expression of genes for specific subsets of chromatin-modifying enzymes. Surprisingly, genome-wide promoter ChIP-chip mapping indicated that the majority of differently expressed genes could be direct targets of TFII-I regulation. The data support the hypothesis that upregulation of TFII-I factors leads to activation of a specific group of developmental genes during mESC differentiation. © 2011 Wiley Periodicals, Inc.

Stem cell potency and the ability to contribute to chimeric organisms.

PubMed

Polejaeva, Irina; Mitalipov, Shoukhrat

2013-03-01

Mouse embryonic chimeras are a well-established tool for studying cell lineage commitment and pluripotency. Experimental chimeras were successfully produced by combining two or more preimplantation embryos or by introducing into host embryo cultured pluripotent embryonic stem cells (ESCs). Chimera production using genetically modified ESCs became the method of choice for the generation of knockout or knockin mice. Although the derivation of ESCs or ESC-like cells has been reported for other species, only mouse and rat pluripotent stem cells have been shown to contribute to germline-competent chimeras, which is the defining feature of ESCs. Herein, we describe different approaches employed for the generation of embryonic chimeras, define chimera-competent cell types, and describe cases of spontaneous chimerism in humans. We also review the current state of derivation of pluripotent stem cells in several species and discuss outcomes of various chimera studies when such cells are used.

Homozygous KSR1 deletion attenuates morbidity but does not prevent tumor development in a mouse model of RAS-driven pancreatic cancer

PubMed Central

Germino, Elizabeth A.; Miller, Joseph P.; Diehl, Lauri; Durinck, Steffen; Modrusan, Zora; Miner, Jeffrey H.

2018-01-01

Given the frequency with which MAP kinase signaling is dysregulated in cancer, much effort has been focused on inhibiting RAS signaling for therapeutic benefit. KSR1, a pseudokinase that interacts with RAF, is a potential target; it was originally cloned in screens for suppressors of constitutively active RAS, and its deletion prevents RAS-mediated transformation of mouse embryonic fibroblasts. In this work, we used a genetically engineered mouse model of pancreatic cancer to assess whether KSR1 deletion would influence tumor development in the setting of oncogenic RAS. We found that Ksr1-/- mice on this background had a modest but significant improvement in all-cause morbidity compared to Ksr1+/+ and Ksr1+/- cohorts. Ksr1-/- mice, however, still developed tumors, and precursor pancreatic intraepithelial neoplastic (PanIN) lesions were detected within a similar timeframe compared to Ksr1+/+ mice. No significant differences in pERK expression or in proliferation were noted. RNA sequencing also did not reveal any unique genetic signature in Ksr1-/- tumors. Further studies will be needed to determine whether and in what settings KSR inhibition may be clinically useful. PMID:29596465

Induced Wnt5a expression perturbs embryonic outgrowth and intestinal elongation, but is well-tolerated in adult mice.

PubMed

Bakker, Elvira R M; Raghoebir, Lalini; Franken, Patrick F; Helvensteijn, Werner; van Gurp, Léon; Meijlink, Frits; van der Valk, Martin A; Rottier, Robbert J; Kuipers, Ernst J; van Veelen, Wendy; Smits, Ron

2012-09-01

Wnt5a is essential during embryonic development, as indicated by mouse Wnt5a knockout embryos displaying outgrowth defects of multiple structures including the gut. The dynamics of Wnt5a involvement in these processes is unclear, and perinatal lethality of Wnt5a knockout embryos has hampered investigation of Wnt5a during postnatal stages in vivo. Although in vitro studies have suggested a relevant role for Wnt5a postnatally, solid evidence for a significant impact of Wnt5a within the complexity of an adult organism is lacking. We generated a tightly-regulated inducible Wnt5a transgenic mouse model and investigated the effects of Wnt5a induction during different time-frames of embryonic development and in adult mice, focusing on the gastrointestinal tract. When induced in embryos from 10.5 dpc onwards, Wnt5a expression led to severe outgrowth defects affecting the gastrointestinal tracts, limbs, facial structures and tails, closely resembling the defects observed in Wnt5a knockout mice. However, Wnt5a induction from 13.5 dpc onwards did not cause this phenotype, indicating that the most critical period for Wnt5a in embryonic development is prior to 13.5 dpc. In adult mice, induced Wnt5a expression did not reveal abnormalities, providing the first in vivo evidence that Wnt5a has no major impact on mouse intestinal homeostasis postnatally. Protein expression of Wnt5a receptor Ror2 was strongly reduced in adult intestine compared to embryonic stages. Moreover, we uncovered a regulatory process where induction of Wnt5a causes downregulation of its receptor Ror2. Taken together, our results indicate a role for Wnt5a during a restricted time-frame of embryonic development, but suggest no impact during homeostatic postnatal stages. Copyright © 2012 Elsevier Inc. All rights reserved.

Laser Fusion of Mouse Embryonic Cells and Intra-Embryonic Fusion of Blastomeres without Affecting the Embryo Integrity

PubMed Central

Krivokharchenko, Alexander; Karmenyan, Artashes; Sarkisov, Oleg; Bader, Michael; Chiou, Arthur; Shakhbazyan, Avetik

2012-01-01

Manipulation with early mammalian embryos is the one of the most important approach to study preimplantation development. Artificial cell fusion is a research tool for various biotechnological experiments. However, the existing methods have various disadvantages, first of them impossibility to fuse selected cells within multicellular structures like mammalian preimplantation embryos. In our experiments we have successfully used high repetition rate picosecond near infrared laser beam for fusion of pairs of oocytes and oocytes with blastomeres. Fused cells looked morphologically normal and keep their ability for further divisions in vitro. We also fused two or three blastomeres inside four-cell mouse embryos. The presence of one, two or three nuclei in different blastomeres of the same early preimplantation mouse embryo was confirmed under UV-light after staining of DNA with the vital dye Hoechst-33342. The most of established embryos demonstrated high viability and developed in vitro to the blastocyst stage. We demonstrated for the first time the use of laser beam for the fusion of various embryonic cells of different size and of two or three blastomeres inside of four-cell mouse embryos without affecting the embryo’s integrity and viability. These embryos with blastomeres of various ploidy maybe unique model for numerous purposes. Thus, we propose laser optical manipulation as a new tool for investigation of fundamental mechanisms of mammalian development. PMID:23227157

Laser fusion of mouse embryonic cells and intra-embryonic fusion of blastomeres without affecting the embryo integrity.

PubMed

Krivokharchenko, Alexander; Karmenyan, Artashes; Sarkisov, Oleg; Bader, Michael; Chiou, Arthur; Shakhbazyan, Avetik

2012-01-01

Manipulation with early mammalian embryos is the one of the most important approach to study preimplantation development. Artificial cell fusion is a research tool for various biotechnological experiments. However, the existing methods have various disadvantages, first of them impossibility to fuse selected cells within multicellular structures like mammalian preimplantation embryos. In our experiments we have successfully used high repetition rate picosecond near infrared laser beam for fusion of pairs of oocytes and oocytes with blastomeres. Fused cells looked morphologically normal and keep their ability for further divisions in vitro. We also fused two or three blastomeres inside four-cell mouse embryos. The presence of one, two or three nuclei in different blastomeres of the same early preimplantation mouse embryo was confirmed under UV-light after staining of DNA with the vital dye Hoechst-33342. The most of established embryos demonstrated high viability and developed in vitro to the blastocyst stage. We demonstrated for the first time the use of laser beam for the fusion of various embryonic cells of different size and of two or three blastomeres inside of four-cell mouse embryos without affecting the embryo's integrity and viability. These embryos with blastomeres of various ploidy maybe unique model for numerous purposes. Thus, we propose laser optical manipulation as a new tool for investigation of fundamental mechanisms of mammalian development.

Microarray Analysis of LTR Retrotransposon Silencing Identifies Hdac1 as a Regulator of Retrotransposon Expression in Mouse Embryonic Stem Cells

PubMed Central

Madej, Monika J.; Taggart, Mary; Gautier, Philippe; Garcia-Perez, Jose Luis; Meehan, Richard R.; Adams, Ian R.

2012-01-01

Retrotransposons are highly prevalent in mammalian genomes due to their ability to amplify in pluripotent cells or developing germ cells. Host mechanisms that silence retrotransposons in germ cells and pluripotent cells are important for limiting the accumulation of the repetitive elements in the genome during evolution. However, although silencing of selected individual retrotransposons can be relatively well-studied, many mammalian retrotransposons are seldom analysed and their silencing in germ cells, pluripotent cells or somatic cells remains poorly understood. Here we show, and experimentally verify, that cryptic repetitive element probes present in Illumina and Affymetrix gene expression microarray platforms can accurately and sensitively monitor repetitive element expression data. This computational approach to genome-wide retrotransposon expression has allowed us to identify the histone deacetylase Hdac1 as a component of the retrotransposon silencing machinery in mouse embryonic stem cells, and to determine the retrotransposon targets of Hdac1 in these cells. We also identify retrotransposons that are targets of other retrotransposon silencing mechanisms such as DNA methylation, Eset-mediated histone modification, and Ring1B/Eed-containing polycomb repressive complexes in mouse embryonic stem cells. Furthermore, our computational analysis of retrotransposon silencing suggests that multiple silencing mechanisms are independently targeted to retrotransposons in embryonic stem cells, that different genomic copies of the same retrotransposon can be differentially sensitive to these silencing mechanisms, and helps define retrotransposon sequence elements that are targeted by silencing machineries. Thus repeat annotation of gene expression microarray data suggests that a complex interplay between silencing mechanisms represses retrotransposon loci in germ cells and embryonic stem cells. PMID:22570599

Investigation for the differentiation process of mouse ES cells by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Yamaguchi, Yoshinori; El-Hagrasy, Maha A.; Shimizu, Eiichi; Saito, Masato; Tamiya, Eiichi

2012-03-01

The arrangement of differentiated pluripotent embryonic stem cells into three-dimensional aggregates, which are known as embryonic bodies, is a main step for progressing the embryonic stem cells differentiation. In this work, embryonic stem cells that were directly produced from the hanging drop step as a three-dimensional structure with no further twodimensional differentiation were diagnosed with Raman spectroscopy as a non-invasive and label-free technique. Raman spectroscopy was employed to discriminate between mouse embryonic bodies of different degrees of maturation. EBs were prepared applying the hanging drop method. The Raman scattering measurements were obtained in vitro with a Nanophoton RAMAN-11 micro-spectrometer (Japan: URL: www.nanophoton.jp equipped with an Olympus XLUM Plan FLN 20X/NA= 1.0 objective lens. Spectral data were smoothed, baseline corrected and normalized to the a welldefined intense 1003 cm-1 band (phenylalanine) which is insensitive to changes in conformation or environment. The differentiation process of embryonic stem cells is initiated by the removal of LIF from culture medium. 1, 7 and 17-dayold embryonic stem cells were collected and investigated by Raman spectroscopy. The main differences involve bands which decreased with maturation such as: 784 cm-1 (U, T, C ring br DNA/RNA, O-P-O str); 1177 cm-1 (cytosine, guanine) and 1578 cm-1 (G, A). It was found that with the progress of differentiation the protein content was amplified. The increase of protein to nucleic acid ratio was also previously observed with the progress of the differentiation process. Raman spectroscopy has the potential to distinguish between the Raman signatures of live embryonic stem cells with different degrees of maturation.

Somatic Donor Cell Type Correlates with Embryonic, but Not Extra-Embryonic, Gene Expression in Postimplantation Cloned Embryos

PubMed Central

Inoue, Kimiko; Ogura, Atsuo

2013-01-01

The great majority of embryos generated by somatic cell nuclear transfer (SCNT) display defined abnormal phenotypes after implantation, such as an increased likelihood of death and abnormal placentation. To gain better insight into the underlying mechanisms, we analyzed genome-wide gene expression profiles of day 6.5 postimplantation mouse embryos cloned from three different cell types (cumulus cells, neonatal Sertoli cells and fibroblasts). The embryos retrieved from the uteri were separated into embryonic (epiblast) and extraembryonic (extraembryonic ectoderm and ectoplacental cone) tissues and were subjected to gene microarray analysis. Genotype- and sex-matched embryos produced by in vitro fertilization were used as controls. Principal component analysis revealed that whereas the gene expression patterns in the embryonic tissues varied according to the donor cell type, those in extraembryonic tissues were relatively consistent across all groups. Within each group, the embryonic tissues had more differentially expressed genes (DEGs) (>2-fold vs. controls) than did the extraembryonic tissues (P<1.0×10–26). In the embryonic tissues, one of the common abnormalities was upregulation of Dlk1, a paternally imprinted gene. This might be a potential cause of the occasional placenta-only conceptuses seen in SCNT-generated mouse embryos (1–5% per embryos transferred in our laboratory), because dysregulation of the same gene is known to cause developmental failure of embryos derived from induced pluripotent stem cells. There were also some DEGs in the extraembryonic tissues, which might explain the poor development of SCNT-derived placentas at early stages. These findings suggest that SCNT affects the embryonic and extraembryonic development differentially and might cause further deterioration in the embryonic lineage in a donor cell-specific manner. This could explain donor cell-dependent variations in cloning efficiency using SCNT. PMID:24146866

Correlation of Versican Expression, Accumulation, and Degradation during Embryonic Development by Quantitative Immunohistochemistry

PubMed Central

Snyder, Jessica M.; Washington, Ida M.; Birkland, Timothy; Chang, Mary Y.; Frevert, Charles W.

2015-01-01

Versican, a chondroitin sulfate proteoglycan, is important in embryonic development, and disruption of the versican gene is embryonically lethal in the mouse. Although several studies show that versican is increased in various organs during development, a focused quantitative study on versican expression and distribution during lung and central nervous system development in the mouse has not previously been performed. We tracked changes in versican (Vcan) gene expression and in the accumulation and degradation of versican. Vcan expression and quantitative immunohistochemistry performed from embryonic day (E) 11.5 to E15.5 showed peak Vcan expression at E13.5 in the lungs and brain. Quantitative mRNA analysis and versican immunohistochemistry showed differences in the expression of the versican isoforms in the embryonic lung and head. The expression of Vcan mRNA and accumulation of versican in tissues was complementary. Immunohistochemistry demonstrated co-localization of versican accumulation and degradation, suggesting distinct roles of versican deposition and degradation in embryogenesis. Very little versican mRNA or protein was found in the lungs of 12- to 16-week-old mice but versican accumulation was significantly increased in mice with Pseudomonas aeruginosa lung infection. These data suggest that versican plays an important role in fundamental, overlapping cellular processes in lung development and infection. PMID:26385570

BROMOCHLORO-HALOACETIC ACIDS: EFFECTS ON MOUSE EMBRYOS IN VITRO AND QSAR CONSIDERATIONS

EPA Science Inventory

The haloacetic acids (HAA) are a family of chemicals that are drinking water disinfection byproducts. We previously reported that bromo- and chloro-acetic acids altered embryonic development when mouse conceptuses were directly exposed to these xenobiotics in whole embryo culture...

Mouse embryonic head as a site for hematopoietic stem cell development.

PubMed

Li, Zhuan; Lan, Yu; He, Wenyan; Chen, Dongbo; Wang, Jun; Zhou, Fan; Wang, Yu; Sun, Huayan; Chen, Xianda; Xu, Chunhong; Li, Sha; Pang, Yakun; Zhang, Guangzhou; Yang, Liping; Zhu, Lingling; Fan, Ming; Shang, Aijia; Ju, Zhenyu; Luo, Lingfei; Ding, Yuqiang; Guo, Wei; Yuan, Weiping; Yang, Xiao; Liu, Bing

2012-11-02

In the mouse embryo, the aorta-gonad-mesonephros (AGM) region is considered to be the sole location for intraembryonic emergence of hematopoietic stem cells (HSCs). Here we report that, in parallel to the AGM region, the E10.5-E11.5 mouse head harbors bona fide HSCs, as defined by long-term, high-level, multilineage reconstitution and self-renewal capacity in adult recipients, before HSCs enter the circulation. The presence of hemogenesis in the midgestation head is indicated by the appearance of intravascular cluster cells and the blood-forming capacity of a sorted endothelial cell population. In addition, lineage tracing via an inducible VE-cadherin-Cre transgene demonstrates the hemogenic capacity of head endothelium. Most importantly, a spatially restricted lineage labeling system reveals the physiological contribution of cerebrovascular endothelium to postnatal HSCs and multilineage hematopoiesis. We conclude that the mouse embryonic head is a previously unappreciated site for HSC emergence within the developing embryo. Copyright © 2012 Elsevier Inc. All rights reserved.

Macrophage migration inhibitory factor acts as a neurotrophin in the developing inner ear.

PubMed

Bank, Lisa M; Bianchi, Lynne M; Ebisu, Fumi; Lerman-Sinkoff, Dov; Smiley, Elizabeth C; Shen, Yu-chi; Ramamurthy, Poornapriya; Thompson, Deborah L; Roth, Therese M; Beck, Christine R; Flynn, Matthew; Teller, Ryan S; Feng, Luming; Llewellyn, G Nicholas; Holmes, Brandon; Sharples, Cyrrene; Coutinho-Budd, Jaeda; Linn, Stephanie A; Chervenak, Andrew P; Dolan, David F; Benson, Jennifer; Kanicki, Ariane; Martin, Catherine A; Altschuler, Richard; Koch, Alisa E; Koch, Alicia E; Jewett, Ethan M; Germiller, John A; Barald, Kate F

2012-12-01

This study is the first to demonstrate that macrophage migration inhibitory factor (MIF), an immune system 'inflammatory' cytokine that is released by the developing otocyst, plays a role in regulating early innervation of the mouse and chick inner ear. We demonstrate that MIF is a major bioactive component of the previously uncharacterized otocyst-derived factor, which directs initial neurite outgrowth from the statoacoustic ganglion (SAG) to the developing inner ear. Recombinant MIF acts as a neurotrophin in promoting both SAG directional neurite outgrowth and neuronal survival and is expressed in both the developing and mature inner ear of chick and mouse. A MIF receptor, CD74, is found on both embryonic SAG neurons and adult mouse spiral ganglion neurons. Mif knockout mice are hearing impaired and demonstrate altered innervation to the organ of Corti, as well as fewer sensory hair cells. Furthermore, mouse embryonic stem cells become neuron-like when exposed to picomolar levels of MIF, suggesting the general importance of this cytokine in neural development.

Establishment of left–right asymmetry in vertebrate development: the node in mouse embryos

PubMed Central

Komatsu, Yoshihiro

2014-01-01

Establishment of vertebrate left–right asymmetry is a critical process for normal embryonic development. After the discovery of genes expressed asymmetrically along the left–right axis in chick embryos in the mid 1990s, the molecular mechanisms responsible for left–right patterning in vertebrate embryos have been studied extensively. In this review article, we discuss the mechanisms by which the initial symmetry along the left–right axis is broken in the mouse embryo. We focus on the role of primary cilia and molecular mechanisms of ciliogenesis at the node when symmetry is broken and left–right asymmetry is established. The node is considered a signaling center for early mouse embryonic development, and the results we review here have led to a better understanding of how the node functions and establishes left–right asymmetry. PMID:23771646

Establishment of left-right asymmetry in vertebrate development: the node in mouse embryos.

PubMed

Komatsu, Yoshihiro; Mishina, Yuji

2013-12-01

Establishment of vertebrate left-right asymmetry is a critical process for normal embryonic development. After the discovery of genes expressed asymmetrically along the left-right axis in chick embryos in the mid 1990s, the molecular mechanisms responsible for left-right patterning in vertebrate embryos have been studied extensively. In this review article, we discuss the mechanisms by which the initial symmetry along the left-right axis is broken in the mouse embryo. We focus on the role of primary cilia and molecular mechanisms of ciliogenesis at the node when symmetry is broken and left-right asymmetry is established. The node is considered a signaling center for early mouse embryonic development, and the results we review here have led to a better understanding of how the node functions and establishes left-right asymmetry.

Meis2 is essential for cranial and cardiac neural crest development.

PubMed

Machon, Ondrej; Masek, Jan; Machonova, Olga; Krauss, Stefan; Kozmik, Zbynek

2015-11-06

TALE-class homeodomain transcription factors Meis and Pbx play important roles in formation of the embryonic brain, eye, heart, cartilage or hematopoiesis. Loss-of-function studies of Pbx1, 2 and 3 and Meis1 documented specific functions in embryogenesis, however, functional studies of Meis2 in mouse are still missing. We have generated a conditional allele of Meis2 in mice and shown that systemic inactivation of the Meis2 gene results in lethality by the embryonic day 14 that is accompanied with hemorrhaging. We show that neural crest cells express Meis2 and Meis2-defficient embryos display defects in tissues that are derived from the neural crest, such as an abnormal heart outflow tract with the persistent truncus arteriosus and abnormal cranial nerves. The importance of Meis2 for neural crest cells is further confirmed by means of conditional inactivation of Meis2 using crest-specific AP2α-IRES-Cre mouse. Conditional mutants display perturbed development of the craniofacial skeleton with severe anomalies in cranial bones and cartilages, heart and cranial nerve abnormalities. Meis2-null mice are embryonic lethal. Our results reveal a critical role of Meis2 during cranial and cardiac neural crest cells development in mouse.

Pipette-based Method to Study Embryoid Body Formation Derived from Mouse and Human Pluripotent Stem Cells Partially Recapitulating Early Embryonic Development Under Simulated Microgravity Conditions

NASA Astrophysics Data System (ADS)

Shinde, Vaibhav; Brungs, Sonja; Hescheler, Jürgen; Hemmersbach, Ruth; Sachinidis, Agapios

2016-06-01

The in vitro differentiation of pluripotent stem cells partially recapitulates early in vivo embryonic development. More recently, embryonic development under the influence of microgravity has become a primary focus of space life sciences. In order to integrate the technique of pluripotent stem cell differentiation with simulated microgravity approaches, the 2-D clinostat compatible pipette-based method was experimentally investigated and adapted for investigating stem cell differentiation processes under simulated microgravity conditions. In order to keep residual accelerations as low as possible during clinorotation, while also guaranteeing enough material for further analysis, stem cells were exposed in 1-mL pipettes with a diameter of 3.5 mm. The differentiation of mouse and human pluripotent stem cells inside the pipettes resulted in the formation of embryoid bodies at normal gravity (1 g) after 24 h and 3 days. Differentiation of the mouse pluripotent stem cells on a 2-D pipette-clinostat for 3 days also resulted in the formation of embryoid bodies. Interestingly, the expression of myosin heavy chain was downregulated when cultivation was continued for an additional 7 days at normal gravity. This paper describes the techniques for culturing and differentiation of pluripotent stem cells and exposure to simulated microgravity during culturing or differentiation on a 2-D pipette clinostat. The implementation of these methodologies along with -omics technologies will contribute to understand the mechanisms regulating how microgravity influences early embryonic development.

Speckle variance optical coherence tomography of blood flow in the beating mouse embryonic heart.

PubMed

Grishina, Olga A; Wang, Shang; Larina, Irina V

2017-05-01

Efficient separation of blood and cardiac wall in the beating embryonic heart is essential and critical for experiment-based computational modelling and analysis of early-stage cardiac biomechanics. Although speckle variance optical coherence tomography (SV-OCT) relying on calculation of intensity variance over consecutively acquired frames is a powerful approach for segmentation of fluid flow from static tissue, application of this method in the beating embryonic heart remains challenging because moving structures generate SV signal indistinguishable from the blood. Here, we demonstrate a modified four-dimensional SV-OCT approach that effectively separates the blood flow from the dynamic heart wall in the beating mouse embryonic heart. The method takes advantage of the periodic motion of the cardiac wall and is based on calculation of the SV signal over the frames corresponding to the same phase of the heartbeat cycle. Through comparison with Doppler OCT imaging, we validate this speckle-based approach and show advantages in its insensitiveness to the flow direction and velocity as well as reduced influence from the heart wall movement. This approach has a potential in variety of applications relying on visualization and segmentation of blood flow in periodically moving structures, such as mechanical simulation studies and finite element modelling. Picture: Four-dimensional speckle variance OCT imaging shows the blood flow inside the beating heart of an E8.5 mouse embryo. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Berberine impairs embryonic development in vitro and in vivo through oxidative stress-mediated apoptotic processes.

PubMed

Huang, Chien-Hsun; Huang, Zi-Wei; Ho, Feng-Ming; Chan, Wen-Hsiung

2018-03-01

Berberine, an isoquinoline alkaloid isolated from several traditional Chinese herbal medicines, has been shown to suppress growth and induce apoptosis in some tumor cell lines. However, berberine has also been reported to attenuate H 2 O 2 -induced oxidative injury and apoptosis. The basis for these ambiguous effects of berberine-triggering or preventing apoptosis-has not been well characterized to date. In the current investigation, we examined whether berberine exerts cytotoxic effects on mouse embryos at the blastocyst stage and affects subsequent embryonic development in vitro and in vivo. Treatment of blastocysts with berberine (2.5-10 μM) induced a significant increase in apoptosis and a corresponding decrease in trophectoderm cell number. Moreover, the implantation success rate of blastocysts pretreated with berberine was lower than that of their control counterparts. Pretreatment with berberine was also associated with increased resorption of postimplantation embryos and decreased fetal weight. In an animal model, intravenous injection of berberine (2, 4, or 6 mg/kg body weight/d) for 4 days resulted in apoptosis of blastocyst cells and early embryonic developmental injury. Berberine-induced injury of mouse blastocysts appeared to be attributable to oxidative stress-triggered intrinsic apoptotic signaling processes that impaired preimplantation and postimplantation embryonic development. Taken together, our results clearly demonstrate that berberine induces apoptosis and retards early preimplantation and postimplantation development of mouse embryos, both in vitro and in vivo. © 2017 Wiley Periodicals, Inc.

Hyperforin inhibits cell proliferation and differentiation in mouse embryonic stem cells.

PubMed

Nakamura, K; Aizawa, K; Yamauchi, J; Tanoue, A

2013-10-01

Hyperforin, a phloroglucinol derivative of St. John's Wort, has been identified as the major molecule responsible for this plant's products anti-depressant effects. It can be expected that exposure to St. John's Wort during pregnancy occurs with some frequency although embryotoxic or teratogenic effects of St. John's Wort and hyperforin have not yet been experimentally examined in detail. In this study, to determine any embryotoxic effects of hyperforin, we have attempted to determine whether hyperforin affects growth and survival processes of employing mouse embryonic stem (mES) cells (representing embryonic tissue) and fibroblasts (representing adult tissues). We used a modified embryonic stem cell test, which has been validated as an in vitro developmental toxicity protocol, mES cells, to assess embryotoxic potential of chemicals under investigation. We have identified that high concentrations of hyperforin inhibited mouse ES cell population growth and induced apoptosis in fibroblasts. Under our cell culture conditions, ES cells mainly differentiated into cardiomyocytes, although various other cell types were also produced. In this condition, hyperforin affected ES cell differentiation into cardiomyocytes in a dose-dependent manner. Analysis of tissue-specific marker expression also revealed that hyperforin at high concentrations partially inhibited ES cell differentiation into mesodermal and endodermal lineages. Hyperforin is currently used in the clinic as a safe and effective antidepressant. Our data indicate that at typical dosages it has only a low risk of embryotoxicity; ingestion of large amounts of hyperforin by pregnant women, however, may pose embryotoxic and teratogenic risks. © 2013 John Wiley & Sons Ltd.

Effects of the EVCAM chemical validation library on differentiation using marker gene expression in lmouse embryonic stem cells

EPA Science Inventory

The adherent cell differentiation and cytotoxicity (ACDC) assay was used to profile the effects of the ECVAM EST validation chemical library (19 compounds) on J1 mouse embryonic stem cells (mESC). PCR-based TaqMan Low Density Arrays (TLDA) provided a high-content assessment of al...

A MICROARRAY ANALYSIS OF GENE EXPRESSION IN THE EMBRYONIC FORELIMB OF THE C57BL/6J MOUSE REVEALS SIGNIFICANT ALTERATIONS METABOLIC AND DEVELOPMENTAL REGULATION FOLLOWING ETHANOL EXPOSURE.

EPA Science Inventory

The observation of transcriptional changes following embryonic ethanol exposure may provide significant insights into the biological response to ethanol exposure. In this study, we used microarray analysis to examine the transcriptional response of the developing limb to a dose ...

Role of Abcg2 During Mouse Embroyonic Stem Cell Diffferentiation

EPA Science Inventory

Role of Abcg2 During Mouse Embryonic Stem Cell Differentiation. Abcg2 is a multidrug resistance ATP-binding cassette (ABC) transporter whose activity may be considered a hallmark of stem cell plasticity. The role of Abcg2 during early embryogenesis, however, is unclear. Studies...

Impaired cardiac energy metabolism in embryos lacking adrenergic stimulation.

PubMed

Baker, Candice N; Gidus, Sarah A; Price, George F; Peoples, Jessica N R; Ebert, Steven N

2015-03-01

As development proceeds from the embryonic to fetal stages, cardiac energy demands increase substantially, and oxidative phosphorylation of ADP to ATP in mitochondria becomes vital. Relatively little, however, is known about the signaling mechanisms regulating the transition from anaerobic to aerobic metabolism that occurs during the embryonic period. The main objective of this study was to test the hypothesis that adrenergic hormones provide critical stimulation of energy metabolism during embryonic/fetal development. We examined ATP and ADP concentrations in mouse embryos lacking adrenergic hormones due to targeted disruption of the essential dopamine β-hydroxylase (Dbh) gene. Embryonic ATP concentrations decreased dramatically, whereas ADP concentrations rose such that the ATP/ADP ratio in the adrenergic-deficient group was nearly 50-fold less than that found in littermate controls by embryonic day 11.5. We also found that cardiac extracellular acidification and oxygen consumption rates were significantly decreased, and mitochondria were significantly larger and more branched in adrenergic-deficient hearts. Notably, however, the mitochondria were intact with well-formed cristae, and there was no significant difference observed in mitochondrial membrane potential. Maternal administration of the adrenergic receptor agonists isoproterenol or l-phenylephrine significantly ameliorated the decreases in ATP observed in Dbh-/- embryos, suggesting that α- and β-adrenergic receptors were effective modulators of ATP concentrations in mouse embryos in vivo. These data demonstrate that adrenergic hormones stimulate cardiac energy metabolism during a critical period of embryonic development. Copyright © 2015 the American Physiological Society.

EXPOSURE TO A P13KINASE INHIBITOR PRODUCED DYSMORPHOGENESIS IN NEURULATION-STAGED MOUSE EMBRYOS IN CULTURE

EPA Science Inventory

The haloacetic acids (HAA) are a family of chemicals that are drinking water disinfection byproducts. We previously reported that bromo- and chloro-acetic acids alter embryonic development when mouse conceptuses are directly exposed to these xenobiotics in whole embryo culture. C...

Sensitive and quantitative detection of botulinum neurotoxin in neurons derived from mouse embryonic stem cells.

PubMed

Pellett, Sabine; Du, Zhong-wei; Pier, Christina L; Tepp, William H; Zhang, Su-chun; Johnson, Eric A

2011-01-07

Botulinum neurotoxins (BoNTs), the most poisonous protein toxins known, represent a serious bioterrorism threat but are also used as a unique and important bio-pharmaceutical to treat an increasing myriad of neurological disorders. The only currently accepted detection method by the United States Food and Drug Administration for biological activity of BoNTs and for potency determination of pharmaceutical preparations is the mouse bioassay (MBA). Recent advances have indicated that cell-based assays using primary neuronal cells can provide an equally sensitive and robust detection platform as the MBA to reliably and quantitatively detect biologically active BoNTs. This study reports for the first time a BoNT detection assay using mouse embryonic stem cells to produce a neuronal cell culture. The data presented indicate that this assay can reliably detect BoNT/A with a similar sensitivity as the MBA. Published by Elsevier Inc.

Wnt/β-catenin and LIF-Stat3 signaling pathways converge on Sp5 to promote mouse embryonic stem cell self-renewal.

PubMed

Ye, Shoudong; Zhang, Dongming; Cheng, Fei; Wilson, Daniel; Mackay, Jeffrey; He, Kan; Ban, Qian; Lv, Feng; Huang, Saifei; Liu, Dahai; Ying, Qi-Long

2016-01-15

Activation of leukemia inhibitor factor (LIF)-Stat3 or Wnt/β-catenin signaling promotes mouse embryonic stem cell (mESC) self-renewal. A myriad of downstream targets have been identified in the individual signal pathways, but their common targets remain largely elusive. In this study, we found that the LIF-Stat3 and Wnt/β-catenin signaling pathways converge on Sp5 to promote mESC self-renewal. Forced Sp5 expression can reproduce partial effects of Wnt/β-catenin signaling but mimics most features of LIF-Stat3 signaling to maintain undifferentiated mESCs. Moreover, Sp5 is able to convert mouse epiblast stem cells into a naïve pluripotent state. Thus, Sp5 is an important component of the regulatory network governing mESC naïve pluripotency. © 2016. Published by The Company of Biologists Ltd.

Derivation of Human Skin Fibroblast Lines for Feeder Cells of Human Embryonic Stem Cells.

PubMed

Unger, Christian; Felldin, Ulrika; Rodin, Sergey; Nordenskjöld, Agneta; Dilber, Sirac; Hovatta, Outi

2016-02-03

After the first derivations of human embryonic stem cell (hESC) lines on fetal mouse feeder cell layers, the idea of using human cells instead of mouse cells as feeder cells soon arose. Mouse cells bear a risk of microbial contamination, and nonhuman immunogenic proteins are absorbed from the feeders to hESCs. Human skin fibroblasts can be effectively used as feeder cells for hESCs. The same primary cell line, which can be safely used for up to 15 passages after stock preparations, can be expanded and used for large numbers of hESC derivations and cultures. These cells are relatively easy to handle and maintain. No animal facilities or animal work is needed. Here, we describe the derivation, culture, and cryopreservation procedures for research-grade human skin fibroblast lines. We also describe how to make feeder layers for hESCs using these fibroblasts. Copyright © 2016 John Wiley & Sons, Inc.

Vertebrate homologues of Frodo are dynamically expressed during embryonic development in tissues undergoing extensive morphogenetic movements.

PubMed

Hunter, Nina L; Hikasa, Hiroki; Dymecki, Susan M; Sokol, Sergei Y

2006-01-01

Frodo has been identified as a protein interacting with Dishevelled, an essential mediator of the Wnt signaling pathway, critical for the determination of cell fate and polarity in embryonic development. In this study, we use specific gene probes to characterize stage- and tissue-specific expression patterns of the mouse Frodo homologue and compare them with Frodo expression patterns in Xenopus embryos. In situ hybridization analysis of mouse Frodo transcripts demonstrates that, similar to Xenopus Frodo, mouse Frodo is expressed in primitive streak mesoderm, neuroectoderm, neural crest, presomitic mesoderm, and somites. In many cases, Frodo expression is confined to tissues undergoing extensive morphogenesis, suggesting that Frodo may be involved in the regulation of cell shape and motility. Highly conserved dynamic expression patterns of Frodo homologues indicate a similar function for these proteins in different vertebrates. 2005 Wiley-Liss, Inc.

The cell cycle of early mammalian embryos: lessons from genetic mouse models.

PubMed

Artus, Jérôme; Babinet, Charles; Cohen-Tannoudji, Michel

2006-03-01

Genes coding for cell cycle components predicted to be essential for its regulation have been shown to be dispensable in mice, at the whole organism level. Such studies have highlighted the extraordinary plasticity of the embryonic cell cycle and suggest that many aspects of in vivo cell cycle regulation remain to be discovered. Here, we discuss the particularities of the mouse early embryonic cell cycle and review the mutations that result in cell cycle defects during mouse early embryogenesis, including deficiencies for genes of the cyclin family (cyclin A2 and B1), genes involved in cell cycle checkpoints (Mad2, Bub3, Chk1, Atr), genes involved in ubiquitin and ubiquitin-like pathways (Uba3, Ubc9, Cul1, Cul3, Apc2, Apc10, Csn2) as well as genes the function of which had not been previously ascribed to cell cycle regulation (Cdc2P1, E4F and Omcg1).

Two Pore Channel 2 Differentially Modulates Neural Differentiation of Mouse Embryonic Stem Cells

PubMed Central

Zhang, Zhe-Hao; Lu, Ying-Ying; Yue, Jianbo

2013-01-01

Nicotinic acid adenine dinucleotide phosphate (NAADP) is an endogenous Ca2+ mobilizing nucleotide presented in various species. NAADP mobilizes Ca2+ from acidic organelles through two pore channel 2 (TPC2) in many cell types and it has been previously shown that NAADP can potently induce neuronal differentiation in PC12 cells. Here we examined the role of TPC2 signaling in the neural differentiation of mouse embryonic stem (ES) cells. We found that the expression of TPC2 was markedly decreased during the initial ES cell entry into neural progenitors, and the levels of TPC2 gradually rebounded during the late stages of neurogenesis. Correspondingly, TPC2 knockdown accelerated mouse ES cell differentiation into neural progenitors but inhibited these neural progenitors from committing to neurons. Overexpression of TPC2, on the other hand, inhibited mouse ES cell from entering the early neural lineage. Interestingly, TPC2 knockdown had no effect on the differentiation of astrocytes and oligodendrocytes of mouse ES cells. Taken together, our data indicate that TPC2 signaling plays a temporal and differential role in modulating the neural lineage entry of mouse ES cells, in that TPC2 signaling inhibits ES cell entry to early neural progenitors, but is required for late neuronal differentiation. PMID:23776607

De novo formation of nucleoli in developing mouse embryos originating from enucleolated zygotes.

PubMed

Kyogoku, Hirohisa; Fulka, Josef; Wakayama, Teruhiko; Miyano, Takashi

2014-06-01

The large, compact oocyte nucleoli, sometimes referred to as nucleolus precursor bodies (NPBs), are essential for embryonic development in mammals; in their absence, the oocytes complete maturation and can be fertilized, but no nucleoli are formed in the zygote or embryo, leading to developmental failure. It has been convincingly documented that zygotes inherit the oocyte nucleolar material and form NPBs again in pronuclei. It is commonly accepted that during early embryonic development, the original compact zygote NPBs gradually transform into reticulated nucleoli of somatic cells. Here, we show that zygote NPBs are not required for embryonic and full-term development in the mouse. When NPBs were removed from late-stage zygotes by micromanipulation, the enucleolated zygotes developed to the blastocyst stage and, after transfer to recipients, live pups were obtained. We also describe de novo formation of nucleoli in developing embryos. After removal of NPBs from zygotes, they formed new nucleoli after several divisions. These results indicate that the zygote NPBs are not used in embryonic development and that the nucleoli in developing embryos originate from de novo synthesized materials. © 2014. Published by The Company of Biologists Ltd.

ESCAPE: database for integrating high-content published data collected from human and mouse embryonic stem cells.

PubMed

Xu, Huilei; Baroukh, Caroline; Dannenfelser, Ruth; Chen, Edward Y; Tan, Christopher M; Kou, Yan; Kim, Yujin E; Lemischka, Ihor R; Ma'ayan, Avi

2013-01-01

High content studies that profile mouse and human embryonic stem cells (m/hESCs) using various genome-wide technologies such as transcriptomics and proteomics are constantly being published. However, efforts to integrate such data to obtain a global view of the molecular circuitry in m/hESCs are lagging behind. Here, we present an m/hESC-centered database called Embryonic Stem Cell Atlas from Pluripotency Evidence integrating data from many recent diverse high-throughput studies including chromatin immunoprecipitation followed by deep sequencing, genome-wide inhibitory RNA screens, gene expression microarrays or RNA-seq after knockdown (KD) or overexpression of critical factors, immunoprecipitation followed by mass spectrometry proteomics and phosphoproteomics. The database provides web-based interactive search and visualization tools that can be used to build subnetworks and to identify known and novel regulatory interactions across various regulatory layers. The web-interface also includes tools to predict the effects of combinatorial KDs by additive effects controlled by sliders, or through simulation software implemented in MATLAB. Overall, the Embryonic Stem Cell Atlas from Pluripotency Evidence database is a comprehensive resource for the stem cell systems biology community. Database URL: http://www.maayanlab.net/ESCAPE

Deficiency of Suppressor Enhancer Lin12 1 Like (SEL1L) in Mice Leads to Systemic Endoplasmic Reticulum Stress and Embryonic Lethality*

PubMed Central

Francisco, Adam B.; Singh, Rajni; Li, Shuai; Vani, Anish K.; Yang, Liu; Munroe, Robert J.; Diaferia, Giuseppe; Cardano, Marina; Biunno, Ida; Qi, Ling; Schimenti, John C.; Long, Qiaoming

2010-01-01

Stress in the endoplasmic reticulum (ER) plays an important causal role in the pathogenesis of several chronic diseases such as Alzheimer, Parkinson, and diabetes mellitus. Insight into the genetic determinants responsible for ER homeostasis will greatly facilitate the development of therapeutic strategies for the treatment of these debilitating diseases. Suppressor enhancer Lin12 1 like (SEL1L) is an ER membrane protein and was thought to be involved in the quality control of secreted proteins. Here we show that the mice homozygous mutant for SEL1L were embryonic lethal. Electron microscopy studies revealed a severely dilated ER in the fetal liver of mutant embryos, indicative of alteration in ER homeostasis. Consistent with this, several ER stress responsive genes were significantly up-regulated in the mutant embryos. Mouse embryonic fibroblast cells deficient in SEL1L exhibited activated unfolded protein response at the basal state, impaired ER-associated protein degradation, and reduced protein secretion. Furthermore, markedly increased apoptosis was observed in the forebrain and dorsal root ganglions of mutant embryos. Taken together, our results demonstrate an essential role for SEL1L in protein quality control during mouse embryonic development. PMID:20197277

Deficiency of suppressor enhancer Lin12 1 like (SEL1L) in mice leads to systemic endoplasmic reticulum stress and embryonic lethality.

PubMed

Francisco, Adam B; Singh, Rajni; Li, Shuai; Vani, Anish K; Yang, Liu; Munroe, Robert J; Diaferia, Giuseppe; Cardano, Marina; Biunno, Ida; Qi, Ling; Schimenti, John C; Long, Qiaoming

2010-04-30

Stress in the endoplasmic reticulum (ER) plays an important causal role in the pathogenesis of several chronic diseases such as Alzheimer, Parkinson, and diabetes mellitus. Insight into the genetic determinants responsible for ER homeostasis will greatly facilitate the development of therapeutic strategies for the treatment of these debilitating diseases. Suppressor enhancer Lin12 1 like (SEL1L) is an ER membrane protein and was thought to be involved in the quality control of secreted proteins. Here we show that the mice homozygous mutant for SEL1L were embryonic lethal. Electron microscopy studies revealed a severely dilated ER in the fetal liver of mutant embryos, indicative of alteration in ER homeostasis. Consistent with this, several ER stress responsive genes were significantly up-regulated in the mutant embryos. Mouse embryonic fibroblast cells deficient in SEL1L exhibited activated unfolded protein response at the basal state, impaired ER-associated protein degradation, and reduced protein secretion. Furthermore, markedly increased apoptosis was observed in the forebrain and dorsal root ganglions of mutant embryos. Taken together, our results demonstrate an essential role for SEL1L in protein quality control during mouse embryonic development.

The mushroom ribosome-inactivating protein lyophyllin exerts deleterious effects on mouse embryonic development in vitro.

PubMed

Chan, W Y; Ng, T B; Lam, Joyce S Y; Wong, Jack H; Chu, K T; Ngai, P H K; Lam, S K; Wang, H X

2010-01-01

Earlier investigations disclose that some plant ribosome-inactivating proteins (RIPs) adversely affect mouse embryonic development. In the present study, a mushroom RIP, namely lyophyllin from Lyophyllum shimeji, was isolated, partially sequenced, and its translation inhibitory activity determined. Its teratogenicity was studied by using a technique entailing microinjection and postimplantation whole-embryo culture. It was found that embryonic abnormalities during the period of organogenesis from E8.5 to E9.5 were induced by lyophyllin at a concentration as low as 50 microg/ml, and when the lyophyllin concentration was raised, the number of abnormal embryos increased, the final somite number decreased, and the abnormalities increased in severity. The affected embryonic structures included the cranial neural tube, forelimb buds, branchial arches, and body axis, while optic and otic placodes were more resistant. Lyophyllin at a concentration higher than 500 microg/ml also induced forebrain blisters within the cranial mesenchyme. When the abnormal embryos were examined histologically, an increase of cell death was found to be associated with abnormal structures, indicating that cell death may be one of the underlying causes of teratogenicity of the mushroom RIP. This constitutes the first report on the teratogenicity of a mushroom RIP.

Embryonic Stem Cells: Isolation, Characterization and Culture

NASA Astrophysics Data System (ADS)

Amit, Michal; Itskovitz-Eldor, Joseph

Embryonic stem cells are pluripotent cells isolated from the mammalian blastocyst. Traditionally, these cells have been derived and cultured with mouse embryonic fibroblast (MEF) supportive layers, which allow their continuous growth in an undifferentiated state. However, for any future industrial or clinical application hESCs should be cultured in reproducible, defined, and xeno-free culture system, where exposure to animal pathogens is prevented. From their derivation in 1998 the methods for culturing hESCs were significantly improved. This chapter wills discuss hESC characterization and the basic methods for their derivation and maintenance.

Preimplantation death of xenomitochondrial mouse embryo harbouring bovine mitochondria

PubMed Central

Kawahara, Manabu; Koyama, Shiori; Iimura, Satomi; Yamazaki, Wataru; Tanaka, Aiko; Kohri, Nanami; Sasaki, Keisuke; Takahashi, Masashi

2015-01-01

Mitochondria, cellular organelles playing essential roles in eukaryotic cell metabolism, are thought to have evolved from bacteria. The organization of mtDNA is remarkably uniform across species, reflecting its vital and conserved role in oxidative phosphorylation (OXPHOS). Our objectives were to evaluate the compatibility of xenogeneic mitochondria in the development of preimplantation embryos in mammals. Mouse embryos harbouring bovine mitochondria (mtB-M embryos) were prepared by the cell-fusion technique employing the haemagglutinating virus of Japan (HVJ). The mtB-M embryos showed developmental delay at embryonic days (E) 3.5 after insemination. Furthermore, none of the mtB-M embryos could implant into the maternal uterus after embryo transfer, whereas control mouse embryos into which mitochondria from another mouse had been transferred developed as well as did non-manipulated embryos. When we performed quantitative PCR (qPCR) of mouse and bovine ND5, we found that the mtB-M embryos contained 8.3% of bovine mitochondria at the blastocyst stage. Thus, contamination with mitochondria from another species induces embryonic lethality prior to implantation into the maternal uterus. The heteroplasmic state of these xenogeneic mitochondria could have detrimental effects on preimplantation development, leading to preservation of species-specific mitochondrial integrity in mammals. PMID:26416548

Interspecies chimera between primate embryonic stem cells and mouse embryos: Monkey ESCs engraft into mouse embryos, but not post-implantation fetuses

PubMed Central

Simerly, Calvin; McFarland, Dave; Castro, Carlos; Lin, Chih-Cheng; Redinger, Carrie; Jacoby, Ethan; Mich-Basso, Jocelyn; Orwig, Kyle; Mills, Parker; Ahrens, Eric; Navara, Chris; Schatten, Gerald

2016-01-01

Unequivocal evidence for pluripotency in which embryonic stem cells contribute to chimeric offspring has yet to be demonstrated in human or nonhuman primates (NHPs). Here, rhesus and baboons ESCs were investigated in interspecific mouse chimera generated by aggregation or blastocyst injection. Aggregation chimera produced mouse blastocysts with GFP-nhpESCs at the inner cell mass (ICM), and embryo transfers (ETs) generated dimly-fluorescencing abnormal fetuses. Direct injection of GFP-nhpESCs into blastocysts produced normal non-GFP-fluorescencing fetuses. Injected chimera showed >70% loss of GFP-nhpESCs after 21 h culture. Outgrowths of all chimeric blastocysts established distinct but separate mouse- and NHP-ESC colonies. Extensive endogenous autofluorescence compromised anti-GFP detection and PCR analysis did not detect nhpESCs in fetuses. NhpESCs localize to the ICM in chimera and generate pregnancies. Because primate ESCs do not engraft post-implantation, and also because endogenous autofluorescence results in misleading positive signals, interspecific chimera assays for pluripotency with primate stem cells is unreliable with the currently available ESCs. Testing primate ESCs reprogrammed into even more naïve states in these inter-specific chimera assays will be an important future endeavor. PMID:21543277

Differentiation of mouse embryonic stem cells into cardiomyocytes via the hanging-drop and mass culture methods.

PubMed

Fuegemann, Christopher J; Samraj, Ajoy K; Walsh, Stuart; Fleischmann, Bernd K; Jovinge, Stefan; Breitbach, Martin

2010-12-01

Herein, we describe two protocols for the in vitro differentiation of mouse embryonic stem cells (mESCs) into cardiomyocytes. mESCs are pluripotent and can be differentiated into cells of all three germ layers, including cardiomyocytes. The methods described here facilitate the differentiation of mESCs into the different cardiac subtypes (atrial-, ventricular-, nodal-like cells). The duration of cell culture determines whether preferentially early- or late-developmental stage cardiomyocytes can be obtained preferentially. This approach allows the investigation of cardiomyocyte development and differentiation in vitro, and also allows for the enrichment and isolation of physiologically intact cardiomyocytes for transplantation purposes. © 2010 by John Wiley & Sons, Inc.

[Programmed mouse genome modifications].

PubMed

Babinet, C

1998-02-01

The availability, in the mouse, of embryonic stem cells (ES cells) which have the ability to colonize the germ line of a developing embryo, has opened entirely new avenues to the genetic approach of embryonic development, physiology and pathology of this animal. Indeed, it is now possible, using homologous recombination in ES cells, to introduce mutations in any gene as long as it has been cloned. Thus, null as well as more subtle mutations can be created. Furthermore, scenarios are currently being derived which will allow one to generate conditional mutations. Taken together, these methods offer a tremendous tool to study gene function in vivo; they also open the way to creating murine models of human genetic diseases.

Cell death and morphogenesis during early mouse development: Are they interconnected?

PubMed Central

Bedzhov, Ivan; Zernicka-Goetz, Magdalena

2015-01-01

Shortly after implantation the embryonic lineage transforms from a coherent ball of cells into polarized cup shaped epithelium. Recently we elucidated a previously unknown apoptosis-independent morphogenic event that reorganizes the pluripotent lineage. Polarization cues from the surrounding basement membrane rearrange the epiblast into a polarized rosette-like structure, where subsequently a central lumen is established. Thus, we provided a new model revising the current concept of apoptosis-dependent epiblast morphogenesis. Cell death however has to be tightly regulated during embryogenesis to ensure developmental success. Here, we follow the stages of early mouse development and take a glimpse at the critical signaling and morphogenic events that determine cells destiny and reshape the embryonic lineage. PMID:25640415

Placenta Defects and Embryonic Lethality Resulting from Disruption of Mouse Hydroxysteroid (17-β) Dehydrogenase 2 Gene

PubMed Central

Rantakari, Pia; Strauss, Leena; Kiviranta, Riku; Lagerbohm, Heidi; Paviala, Jenni; Holopainen, Irma; Vainio, Seppo; Pakarinen, Pirjo; Poutanen, Matti

2008-01-01

Hydroxysteroid (17-β) dehydrogenase 2 (HSD17B2) is a member of aldo-keto reductase superfamily, known to catalyze the inactivation of 17β-hydroxysteroids to less active 17-keto forms and catalyze the conversion of 20α-hydroxyprogesterone to progesterone in vitro. To examine the role of HSD17B2 in vivo, we generated mice deficient in Hsd17b2 [HSD17B2 knockout (KO)] by a targeted gene disruption in embryonic stem cells. From the homozygous mice carrying the disrupted Hsd17b2, 70% showed embryonic lethality appearing at the age of embryonic d 11.5 onward. The embryonic lethality was associated with reduced placental size measured at embryonic d 17.5. The HSD17B2KO mice placentas presented with structural abnormalities in all three major layers: the decidua, spongiotrophoblast, and labyrinth. Most notable was the disruption of the spongiotrophoblast and labyrinthine layers, together with liquid-filled cysts in the junctional region and the basal layer. Treatments with an antiestrogen or progesterone did not rescue the embryonic lethality or the placenta defect in the homozygous mice. In hybrid background used, 24% of HSD17B2KO mice survived through the fetal period but were born growth retarded and displayed a phenotype in the brain with enlargement of ventricles, abnormal laminar organization, and increased cellular density in the cortex. Furthermore, the HSD17B2KO mice had unilateral renal degeneration, the affected kidney frequently appearing as a fluid-filled sac. Our results provide evidence for a role for HSD17B2 enzyme in the cellular organization of the mouse placenta. PMID:18048640

Importance of the pluripotency factor LIN28 in the mammalian nucleolus during early embryonic development.

PubMed

Vogt, Edgar J; Meglicki, Maciej; Hartung, Kristina Ilka; Borsuk, Ewa; Behr, Rüdiger

2012-12-01

The maternal nucleolus is required for proper activation of the embryonic genome (EGA) and early embryonic development. Nucleologenesis is characterized by the transformation of a nucleolar precursor body (NPB) to a mature nucleolus during preimplantation development. However, the function of NPBs and the involved molecular factors are unknown. We uncover a novel role for the pluripotency factor LIN28, the biological significance of which was previously demonstrated in the reprogramming of human somatic cells to induced pluripotent stem (iPS) cells. Here, we show that LIN28 accumulates at the NPB and the mature nucleolus in mouse preimplantation embryos and embryonic stem cells (ESCs), where it colocalizes with the nucleolar marker B23 (nucleophosmin 1). LIN28 has nucleolar localization in non-human primate (NHP) preimplantation embryos, but is cytoplasmic in NHP ESCs. Lin28 transcripts show a striking decline before mouse EGA, whereas LIN28 protein localizes to NPBs at the time of EGA. Following knockdown with a Lin28 morpholino, the majority of embryos arrest between the 2- and 4-cell stages and never develop to morula or blastocyst. Lin28 morpholino-injected embryos arrested at the 2-cell stage were not enriched with nucleophosmin at presumptive NPB sites, indicating that functional NPBs were not assembled. Based on these results, we propose that LIN28 is an essential factor of nucleologenesis during early embryonic development.

The vertebrate phylotypic stage and an early bilaterian-related stage in mouse embryogenesis defined by genomic information.

PubMed

Irie, Naoki; Sehara-Fujisawa, Atsuko

2007-01-12

Embryos of taxonomically different vertebrates are thought to pass through a stage in which they resemble one another morphologically. This "vertebrate phylotypic stage" may represent the basic vertebrate body plan that was established in the common ancestor of vertebrates. However, much controversy remains about when the phylotypic stage appears, and whether it even exists. To overcome the limitations of studies based on morphological comparison, we explored a comprehensive quantitative method for defining the constrained stage using expressed sequence tag (EST) data, gene ontologies (GO), and available genomes of various animals. If strong developmental constraints occur during the phylotypic stage of vertebrate embryos, then genes conserved among vertebrates would be highly expressed at this stage. We established a novel method for evaluating the ancestral nature of mouse embryonic stages that does not depend on comparative morphology. The numerical "ancestor index" revealed that the mouse indeed has a highly conserved embryonic period at embryonic day 8.0-8.5, the time of appearance of the pharyngeal arch and somites. During this period, the mouse prominently expresses GO-determined developmental genes shared among vertebrates. Similar analyses revealed the existence of a bilaterian-related period, during which GO-determined developmental genes shared among bilaterians are markedly expressed at the cleavage-to-gastrulation period. The genes associated with the phylotypic stage identified by our method are essential in embryogenesis. Our results demonstrate that the mid-embryonic stage of the mouse is indeed highly constrained, supporting the existence of the phylotypic stage. Furthermore, this candidate stage is preceded by a putative bilaterian ancestor-related period. These results not only support the developmental hourglass model, but also highlight the hierarchical aspect of embryogenesis proposed by von Baer. Identification of conserved stages and tissues by this method in various animals would be a powerful tool to examine the phylotypic stage hypothesis, and to understand which kinds of developmental events and gene sets are evolutionarily constrained and how they limit the possible variations of animal basic body plans.

Zscan4 is regulated by PI3-kinase and DNA-damaging agents and directly interacts with the transcriptional repressors LSD1 and CtBP2 in mouse embryonic stem cells.

PubMed

Storm, Michael P; Kumpfmueller, Benjamin; Bone, Heather K; Buchholz, Michael; Sanchez Ripoll, Yolanda; Chaudhuri, Julian B; Niwa, Hitoshi; Tosh, David; Welham, Melanie J

2014-01-01

The Zscan4 family of genes, encoding SCAN-domain and zinc finger-containing proteins, has been implicated in the control of early mammalian embryogenesis as well as the regulation of pluripotency and maintenance of genome integrity in mouse embryonic stem cells. However, many features of this enigmatic family of genes are poorly understood. Here we show that undifferentiated mouse embryonic stem cell (ESC) lines simultaneously express multiple members of the Zscan4 gene family, with Zscan4c, Zscan4f and Zscan4-ps2 consistently being the most abundant. Despite this, between only 0.1 and 0.7% of undifferentiated mouse pluripotent stem cells express Zscan4 protein at a given time, consistent with a very restricted pattern of Zscan4 transcripts reported previously. Herein we demonstrate that Zscan4 expression is regulated by the p110α catalytic isoform of phosphoinositide 3-kinases and is induced following exposure to a sub-class of DNA-damage-inducing agents, including Zeocin and Cisplatin. Furthermore, we observe that Zscan4 protein expression peaks during the G2 phase of the cell cycle, suggesting that it may play a critical role at this checkpoint. Studies with GAL4-fusion proteins suggest a role for Zscan4 in transcriptional regulation, further supported by the fact that protein interaction analyses demonstrate that Zscan4 interacts with both LSD1 and CtBP2 in ESC nuclei. This study advances and extends our understanding of Zscan4 expression, regulation and mechanism of action. Based on our data we propose that Zscan4 may regulate gene transcription in mouse ES cells through interaction with LSD1 and CtBP2.

Zscan4 Is Regulated by PI3-Kinase and DNA-Damaging Agents and Directly Interacts with the Transcriptional Repressors LSD1 and CtBP2 in Mouse Embryonic Stem Cells

PubMed Central

Bone, Heather K.; Buchholz, Michael; Sanchez Ripoll, Yolanda; Chaudhuri, Julian B.; Niwa, Hitoshi; Tosh, David; Welham, Melanie J.

2014-01-01

The Zscan4 family of genes, encoding SCAN-domain and zinc finger-containing proteins, has been implicated in the control of early mammalian embryogenesis as well as the regulation of pluripotency and maintenance of genome integrity in mouse embryonic stem cells. However, many features of this enigmatic family of genes are poorly understood. Here we show that undifferentiated mouse embryonic stem cell (ESC) lines simultaneously express multiple members of the Zscan4 gene family, with Zscan4c, Zscan4f and Zscan4-ps2 consistently being the most abundant. Despite this, between only 0.1 and 0.7% of undifferentiated mouse pluripotent stem cells express Zscan4 protein at a given time, consistent with a very restricted pattern of Zscan4 transcripts reported previously. Herein we demonstrate that Zscan4 expression is regulated by the p110α catalytic isoform of phosphoinositide 3-kinases and is induced following exposure to a sub-class of DNA-damage-inducing agents, including Zeocin and Cisplatin. Furthermore, we observe that Zscan4 protein expression peaks during the G2 phase of the cell cycle, suggesting that it may play a critical role at this checkpoint. Studies with GAL4-fusion proteins suggest a role for Zscan4 in transcriptional regulation, further supported by the fact that protein interaction analyses demonstrate that Zscan4 interacts with both LSD1 and CtBP2 in ESC nuclei. This study advances and extends our understanding of Zscan4 expression, regulation and mechanism of action. Based on our data we propose that Zscan4 may regulate gene transcription in mouse ES cells through interaction with LSD1 and CtBP2. PMID:24594919

Generation of a mouse model with a reversible hypomorphic cytochrome P450 reductase gene: utility for tissue-specific rescue of the reductase expression, and insights from a resultant mouse model with global suppression of P450 reductase expression in extrahepatic tissues.

PubMed

Wei, Yuan; Zhou, Xin; Fang, Cheng; Li, Lei; Kluetzman, Kerri; Yang, Weizhu; Zhang, Qing-Yu; Ding, Xinxin

2010-07-01

A mouse model termed Cpr-low (CL) was recently generated, in which the expression of the cytochrome P450 reductase (Cpr) gene was globally down-regulated. The decreased CPR expression was accompanied by phenotypical changes, including reduced embryonic survival, decreases in circulating cholesterol, increases in hepatic P450 expression, and female infertility (accompanied by elevated serum testosterone and progesterone levels). In the present study, a complementary mouse model [named reversible-CL (r-CL)] was generated, in which the reduced CPR expression can be reversed in an organ-specific fashion. The neo cassette, which was inserted into the last Cpr intron in r-CL mice, can be deleted by Cre recombinase, thus returning the structure of the Cpr gene (and hence CPR expression) to normal in Cre-expressing cells. All previously identified phenotypes of the CL mice were preserved in the r-CL mice. As a first application of the r-CL model, we have generated an extrahepatic-CL (xh-CL) mouse for testing of the functions of CPR-dependent enzymes in all extrahepatic tissues. The xh-CL mice, generated by mating of r-CL mice with albumin-Cre mice, had normal CPR expression in hepatocytes but down-regulated CPR expression elsewhere. They were indistinguishable from wild-type mice in body and liver weights, circulating cholesterol levels, and hepatic microsomal P450 expression and activities; however, they still showed elevated serum testosterone and progesterone levels and sterility in females. Embryonic lethality was prevented in males, but apparently not in females, indicating a critical role for fetal hepatic CPR-dependent enzymes in embryonic development, at least in males.

Spatial distribution of endogenous retinoids in the murine embryonic mandible.

PubMed

Kronmiller, J E; Beeman, C S

1994-12-01

Retinoids play an important part in pattern formation during embryonic development. Exogenous retinoids alter the pattern of skeletal, neural and odontogenic tissues. Endogenous retinoids have been demonstrated previously in the murine embryonic mandible, reaching a concentration peak during the initiation of odontogenesis. It was now found that endogenous retinoids are present in a concentration gradient in the embryonic mouse mandible at the time of the initiation of the dental lamina. All-trans-retinoic acid was more concentrated in the incisor region and retinol in the molar region. These results, and the fact that exogenous retinoids produce supernumerary incisors and missing molars, suggest that all-trans-retinoic acid may instruct incisor morphology.

Metastable primordial germ cell-like state induced from mouse embryonic stem cells by Akt activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamano, Noriko; Kimura, Tohru, E-mail: tkimura@patho.med.osaka-u.ac.jp; Watanabe-Kushima, Shoko

Specification to primordial germ cells (PGCs) is mediated by mesoderm-induction signals during gastrulation. We found that Akt activation during in vitro mesodermal differentiation of embryonic stem cells (ESCs) generated self-renewing spheres with differentiation states between those of ESCs and PGCs. Essential regulators for PGC specification and their downstream germ cell-specific genes were expressed in the spheres, indicating that the sphere cells had commenced differentiation to the germ lineage. However, the spheres did not proceed to spermatogenesis after transplantation into testes. Sphere cell transfer to the original feeder-free ESC cultures resulted in chaotic differentiation. In contrast, when the spheres were culturedmore » on mouse embryonic fibroblasts or in the presence of ERK-cascade and GSK3 inhibitors, reversion to the ESC-like state was observed. These results indicate that Akt signaling promotes a novel metastable and pluripotent state that is intermediate to those of ESCs and PGCs.« less

Mouse embryonic stem cell culture for generation of three-dimensional retinal and cortical tissues.

PubMed

Eiraku, Mototsugu; Sasai, Yoshiki

2011-12-15

Generation of compound tissues with complex structures is a major challenge in cell biology. In this article, we describe a protocol for mouse embryonic stem cell (ESC) culture for in vitro generation of three-dimensional retinal tissue, comparing it with the culture protocol for cortical tissue generation. Dissociated ESCs are reaggregated in a 96-well plate with reduced cell-plate adhesion and cultured as floating aggregates. Retinal epithelium is efficiently generated when ESC aggregates are cultured in serum-free medium containing extracellular matrix proteins, spontaneously forming hemispherical vesicles and then progressively transforming into a shape reminiscent of the embryonic optic cup in 9-10 d. In long-term culture, the ESC-derived optic cup generates a fully stratified retinal tissue consisting of all major neural retinal components. In contrast, the cortical differentiation culture can be started without exogenous extracellular matrix proteins, and it generates stratified cortical epithelia consisting of four distinct layers in 13 d.

A simple in vitro culture system for tracheal cartilage development.

PubMed

Park, Jinhyung; Zhang, Jennifer J R; Choi, Ruth; Trinh, Irene; Kim, Peter C W

2010-02-01

Semi-circular tracheal cartilage is a critical determinant of maintaining architectural integrity of the respiratory airway. The current effort to understand the morphogenesis of tracheal cartilage is challenged by the lack of appropriate model systems. Here we report an in vitro tracheal cartilage system using embryonic tracheal–lung explants to recapitulate in vivo tracheal cartilage developmental processes. With modifications of a current lung culture protocol, we report a consistent in vitro technique of culturing tracheal cartilage from primitive mouse embryonic foregut for the first time. This tracheal culture system not only induces the formation of tracheal cartilage from the mouse embryonic foregut but also allows for the proper patterning of the developed tracheal cartilage. Furthermore, we show that this culture technique can be applied to culturing other types of cartilage in vertebrae, limbs, and ribs. We believe that this novel application of our in vitro culture system will facilitate the manipulation of cartilage development under various conditions and thus enabling us to advance our current limited knowledge on cartilage biology and development.

CBX7 gene expression plays a negative role in adipocyte cell growth and differentiation

PubMed Central

Forzati, Floriana; Federico, Antonella; Pallante, Pierlorenzo; Colamaio, Marianna; Esposito, Francesco; Sepe, Romina; Gargiulo, Sara; Luciano, Antonio; Arra, Claudio; Palma, Giuseppe; Bon, Giulia; Bucher, Stefania; Falcioni, Rita; Brunetti, Arturo; Battista, Sabrina; Fedele, Monica; Fusco, Alfredo

2014-01-01

ABSTRACT We have recently generated knockout mice for the Cbx7 gene, coding for a polycomb group protein that is downregulated in human malignant neoplasias. These mice develop liver and lung adenomas and carcinomas, which confirms a tumour suppressor role for CBX7. The CBX7 ability to downregulate CCNE1 expression likely accounts for the phenotype of the Cbx7-null mice. Unexpectedly, Cbx7-knockout mice had a higher fat tissue mass than wild-type, suggesting a role of CBX7 in adipogenesis. Consistently, we demonstrate that Cbx7-null mouse embryonic fibroblasts go towards adipocyte differentiation more efficiently than their wild-type counterparts, and this effect is Cbx7 dose-dependent. Similar results were obtained when Cbx7-null embryonic stem cells were induced to differentiate into adipocytes. Conversely, mouse embryonic fibroblasts and human adipose-derived stem cells overexpressing CBX7 show an opposite behaviour. These findings support a negative role of CBX7 in the control of adipocyte cell growth and differentiation. PMID:25190058

Derivation of Pluripotent Stem Cells with In Vivo Embryonic and Extraembryonic Potency.

PubMed

Yang, Yang; Liu, Bei; Xu, Jun; Wang, Jinlin; Wu, Jun; Shi, Cheng; Xu, Yaxing; Dong, Jiebin; Wang, Chengyan; Lai, Weifeng; Zhu, Jialiang; Xiong, Liang; Zhu, Dicong; Li, Xiang; Yang, Weifeng; Yamauchi, Takayoshi; Sugawara, Atsushi; Li, Zhongwei; Sun, Fangyuan; Li, Xiangyun; Li, Chen; He, Aibin; Du, Yaqin; Wang, Ting; Zhao, Chaoran; Li, Haibo; Chi, Xiaochun; Zhang, Hongquan; Liu, Yifang; Li, Cheng; Duo, Shuguang; Yin, Ming; Shen, Huan; Belmonte, Juan Carlos Izpisua; Deng, Hongkui

2017-04-06

Of all known cultured stem cell types, pluripotent stem cells (PSCs) sit atop the landscape of developmental potency and are characterized by their ability to generate all cell types of an adult organism. However, PSCs show limited contribution to the extraembryonic placental tissues in vivo. Here, we show that a chemical cocktail enables the derivation of stem cells with unique functional and molecular features from mice and humans, designated as extended pluripotent stem (EPS) cells, which are capable of chimerizing both embryonic and extraembryonic tissues. Notably, a single mouse EPS cell shows widespread chimeric contribution to both embryonic and extraembryonic lineages in vivo and permits generating single-EPS-cell-derived mice by tetraploid complementation. Furthermore, human EPS cells exhibit interspecies chimeric competency in mouse conceptuses. Our findings constitute a first step toward capturing pluripotent stem cells with extraembryonic developmental potentials in culture and open new avenues for basic and translational research. VIDEO ABSTRACT. Copyright © 2017 Elsevier Inc. All rights reserved.

Wnt inhibition promotes vascular specification of embryonic cardiac progenitors

PubMed Central

Reichman, David E.; Park, Laura; Man, Limor; Redmond, David; Chao, Kenny; Harvey, Richard P.; Taketo, Makoto M.; Rosenwaks, Zev

2018-01-01

ABSTRACT Several studies have demonstrated a multiphasic role for Wnt signaling during embryonic cardiogenesis and developed protocols that enrich for cardiac derivatives during in vitro differentiation of human pluripotent stem cells (hPSCs). However, few studies have investigated the role of Wnt signaling in the specification of cardiac progenitor cells (CPCs) toward downstream fates. Using transgenic mice and hPSCs, we tracked endothelial cells (ECs) that originated from CPCs expressing NKX2.5. Analysis of EC-fated CPCs at discrete phenotypic milestones during hPSC differentiation identified reduced Wnt activity as a hallmark of EC specification, and the enforced activation or inhibition of Wnt reduced or increased, respectively, the degree of vascular commitment within the CPC population during both hPSC differentiation and mouse embryogenesis. Wnt5a, which has been shown to exert an inhibitory influence on Wnt signaling during cardiac development, was dynamically expressed during vascular commitment of hPSC-derived CPCs, and ectopic Wnt5a promoted vascular specification of hPSC-derived and mouse embryonic CPCs. PMID:29217753

Induced pluripotent stem cells from goat fibroblasts.

PubMed

Song, Hui; Li, Hui; Huang, Mingrui; Xu, Dan; Gu, Chenghao; Wang, Ziyu; Dong, Fulu; Wang, Feng

2013-12-01

Embryonic stem cells (ESCs) are a powerful model for genetic engineering, studying developmental biology, and modeling disease. To date, ESCs have been established from the mouse (Evans and Kaufman, 1981, Nature 292:154-156), non-human primates (Thomson et al., , Proc Nat Acad Sci USA 92:7844-7848), humans (Thomson et al., 1998, Science 282:1145-1147), and rats (Buehr et al., , Cell 135:1287-1298); however, the derivation of ESCs from domesticated ungulates such as goats, sheep, cattle, and pigs have not been successful. Alternatively, induced pluripotent stem cells (iPSCs) can be generated by reprogramming somatic cells with several combinations of genes encoding transcription factors (OCT3/4, SOX2, KLF4, cMYC, LIN28, and NANOG). To date, iPSCs have been isolated from various species, but only limited information is available regarding goat iPSCs (Ren et al., 2011, Cell Res 21:849-853). The objectives of this study were to generate goat iPSCs from fetal goat primary ear fibroblasts using lentiviral transduction of four human transcription factors: OCT4, SOX2, KLF4, and cMYC. The goat iPSCs were successfully generated by co-culture with mitomycin C-treated mouse embryonic fibroblasts using medium supplemented with knockout serum replacement and human basic fibroblast growth factor. The goat iPSCs colonies are flat, compact, and closely resemble human iPSCs. They have a normal karyotype; stain positive for alkaline phosphatase, OCT4, and NANOG; express endogenous pluripotency genes (OCT4, SOX2, cMYC, and NANOG); and can spontaneously differentiate into three germ layers in vitro and in vivo. © 2013 Wiley Periodicals, Inc.

Reprogramming of somatic cells induced by fusion of embryonic stem cells using hemagglutinating virus of Japan envelope (HVJ-E)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yue, Xiao-shan; Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501; Fujishiro, Masako

In this research, hemagglutinating virus of Japan envelope (HVJ-E) was used to reprogram somatic cells by fusion with mouse embryonic stem (ES) cells. Neomycin-resistant mouse embryonic fibroblasts (MEFs) were used as somatic cells. Nanog-overexpressing puromycin-resistant EB3 cells were used as mouse ES cells. These two cells were fused by exposing to HVJ-E and the generated fusion cells were selected by puromycin and G418 to get the stable fusion cell line. The fusion cells form colonies in feeder-free culture system. Microsatellite analysis of the fusion cells showed that they possessed genes from both ES cells and fibroblasts. The fusion cells weremore » tetraploid, had alkali phosphatase activity, and expressed stem cell marker genes such as Pou5f1, Nanog, and Sox2, but not the fibroblast cell marker genes such as Col1a1 and Col1a2. The pluripotency of fusion cells was confirmed by their expression of marker genes for all the three germ layers after differentiation induction, and by their ability to form teratoma which contained all the three primary layers. Our results show that HVJ-E can be used as a fusion reagent for reprogramming of somatic cells.« less

Acellular Mouse Kidney ECM can be Used as a Three-Dimensional Substrate to Test the Differentiation Potential of Embryonic Stem Cell Derived Renal Progenitors.

PubMed

Sambi, Manpreet; Chow, Theresa; Whiteley, Jennifer; Li, Mira; Chua, Shawn; Raileanu, Vanessa; Rogers, Ian M

2017-08-01

The development of strategies for tissue regeneration and bio-artificial organ development is based on our understanding of embryogenesis. Differentiation protocols attempt to recapitulate the signaling modalities of gastrulation and organogenesis, coupled with cell selection regimens to isolate the cells of choice. This strategy is impeded by the lack of optimal in vitro culture systems since traditional culture systems do not allow for the three-dimensional interaction between cells and the extracellular matrix. While artificial three-dimensional scaffolds are available, using the natural extracellular matrix scaffold is advantageous because it has a distinct architecture that is difficult to replicate. The adult extracellular matrix is predicted to mediate signaling related to tissue repair not embryogenesis but existing similarities between the two argues that the extracellular matrix will influence the differentiation of stem and progenitor cells. Previous studies using undifferentiated embryonic stem cells grown directly on acellular kidney ECM demonstrated that the acellular kidney supported cell growth but limited differentiation occurred. Using mouse kidney extracellular matrix and mouse embryonic stem cells we report that the extracellular matrix can support the development of kidney structures if the stem cells are first differentiated to kidney progenitor cells before being applied to the acellular organ.

Mouse androgenetic embryonic stem cells differentiated to multiple cell lineages in three embryonic germ layers in vitro.

PubMed

Teramura, Takeshi; Onodera, Yuta; Murakami, Hideki; Ito, Syunsuke; Mihara, Toshihiro; Takehara, Toshiyuki; Kato, Hiromi; Mitani, Tasuku; Anzai, Masayuki; Matsumoto, Kazuya; Saeki, Kazuhiro; Fukuda, Kanji; Sagawa, Norimasa; Osoi, Yoshihiko

2009-06-01

The embryos of some rodents and primates can precede early development without the process of fertilization; however, they cease to develop after implantation because of restricted expressions of imprinting genes. Asexually developed embryos are classified into parthenote/gynogenote and androgenote by their genomic origins. Embryonic stem cells (ESCs) derived from asexual origins have also been reported. To date, ESCs derived from parthenogenetic embryos (PgESCs) have been established in some species, including humans, and the possibility to be alternative sources for autologous cell transplantation in regenerative medicine has been proposed. However, some developmental characteristics, which might be important for therapeutic applications, such as multiple differentiation capacity and transplantability of the ESCs of androgenetic origin (AgESCs) are uncertain. Here, we induced differentiation of mouse AgESCs and observed derivation of neural cells, cardiomyocytes and hepatocytes in vitro. Following differentiated embryoid body (EB) transplantation in various mouse strains including the strain of origin, we found that the EBs could engraft in theoretically MHC-matched strains. Our results indicate that AgESCs possess at least two important characteristics, multiple differentiation properties in vitro and transplantability after differentiation, and suggest that they can also serve as a source of histocompatible tissues for transplantation.

Omcg1 is critically required for mitosis in rapidly dividing mouse intestinal progenitors and embryonic stem cells.

PubMed

Léguillier, Teddy; Vandormael-Pournin, Sandrine; Artus, Jérôme; Houlard, Martin; Picard, Christel; Bernex, Florence; Robine, Sylvie; Cohen-Tannoudji, Michel

2012-07-15

Recent studies have shown that factors involved in transcription-coupled mRNA processing are important for the maintenance of genome integrity. How these processes are linked and regulated in vivo remains largely unknown. In this study, we addressed in the mouse model the function of Omcg1, which has been shown to participate in co-transcriptional processes, including splicing and transcription-coupled repair. Using inducible mouse models, we found that Omcg1 is most critically required in intestinal progenitors. In absence of OMCG1, proliferating intestinal epithelial cells underwent abnormal mitosis followed by apoptotic cell death. As a consequence, the crypt proliferative compartment of the small intestine was quickly and totally abrogated leading to the rapid death of the mice. Lack of OMCG1 in embryonic stem cells led to a similar cellular phenotype, with multiple mitotic defects and rapid cell death. We showed that mutant intestinal progenitors and embryonic stem cells exhibited a reduced cell cycle arrest following irradiation, suggesting that mitotic defects may be consecutive to M phase entry with unrepaired DNA damages. These findings unravel a crucial role for pre-mRNA processing in the homeostasis of the small intestine and point to a major role of OMCG1 in the maintenance of genome integrity.

The effect of minimal concentration of ethylene glycol (EG) combined with polyvinylpyrrolidone (PVP) on mouse oocyte survival and subsequent embryonic development following vitrification.

PubMed

Wang, Yao; Okitsu, Osamu; Zhao, Xiao-Ming; Sun, Yun; Di, Wen; Chian, Ri-Cheng

2014-01-01

Vitrification techniques employ a relatively high concentration of cryoprotectant in vitrification solutions. Exposure of oocytes to high concentrations of cryoprotectant is known to damage the oocytes via both cytotoxic and osmotic effects. Therefore, the key to successful vitrification of oocytes is to strike a balance between the usage of minimal concentration of cryoprotectant without compromising their cryoprotective actions. The minimal concentration of ethylene glycol (EG) on mouse oocyte survival and subsequent embryonic development was evaluated following vitrification-warming and parthenogenetic activation. Polyvinylpyrrolidone (PVP) combined with EG on mouse oocyte survival and subsequent embryonic development as well as morphology of the spindle and chromosome alignment were also evaluated. Vitrification system was adapted with JY Straw and the cooling rate was approximately 442-500 °C/min. In contrast, the warming rate was approximately 2,210-2,652 °C/min. Survival rate of oocytes increased significantly when 15 % EG was combined with 2 % PVP in vitrification solution (VS). The effect of combination of EG and PVP was not significant when the concentration of EG was 20 % and higher. Although there were no significant differences in embryonic development, the percentage of abnormal spindle and chromosome alignment was significantly higher in the oocytes without 2 % PVP in VS. Our data provide a proof of principle for oocyte vitrification that may not require a high concentration of cryoprotectant. There are synergic effects of EG combined with PVP for oocyte vitrification, which may provide important information to the field in developing less cytotoxic VS.

Experimental embryology of mammals at the Jastrzebiec Institute of Genetics and Animal Breeding.

PubMed

Karasiewicz, Jolanta; Andrzej-Modlinski, Jacek

2008-01-01

Our Department of Experimental Embryology originated from The Laboratory of Embryo Biotechnology, which was organized and directed by Dr. Maria Czlonkowska until her premature death in 1991. Proving successful international transfer of frozen equine embryos and generation of an embryonic sheep-goat chimaera surviving ten years were outstanding achievements of her term. In the 1990s, we produced advanced fetuses of mice after reconstructing enucleated oocytes with embryonic stem (ES) cells, as well as mice originating entirely from ES cells by substitution of the inner cell mass with ES cells. Attempts at obtaining ES cells in sheep resulted in the establishment of embryo-derived epithelioid cell lines from Polish Heatherhead and Polish Merino breeds, producing overt chimaeras upon blastocyst injection. Successful re-cloning was achieved from 8-cell rabbit embryos, and healthy animals were born from the third generation of cloned embryos. Recently mice were born after transfer of 8-cell embryonic nuclei into selectively enucleated zygotes, and mouse blastocysts were produced from selectively enucleated germinal vesicle oocytes surrounded by follicular cells, upon their reconstruction with 2-cell nuclei and subsequent activation. Embryonic-somatic chimaeras were born after transfer of foetal fibroblasts into 8-cell embryos (mouse) and into morulae and blastocysts (sheep). We also regularly perform the following applications: in vitro production of bovine embryos from slaughterhouse oocytes or those recovered by ovum pick up; cryopreservation of oocytes and embryos (freezing: mouse, rabbit, sheep, goat; vitrification: rabbit, cow); and banking of somatic cells from endangered wild mammalian species (mainly Cervidae).

Citrinin induces apoptosis via a mitochondria-dependent pathway and inhibition of survival signals in embryonic stem cells, and causes developmental injury in blastocysts

PubMed Central

Chan, Wen-Hsiung

2007-01-01

The mycotoxin CTN (citrinin), a natural contaminant in foodstuffs and animal feeds, has cytotoxic and genotoxic effects on various mammalian cells. CTN is known to cause cell injury, including apoptosis, but the precise regulatory mechanisms of CTN action, particularly in stem cells and embryos, are currently unclear. In the present paper, I report that CTN has cytotoxic effects on mouse embryonic stem cells and blastocysts, and is associated with defects in their subsequent development, both in vitro and in vivo. Experiments in embryonic stem cells (ESC-B5) showed that CTN induces apoptosis via ROS (reactive oxygen species) generation, increased Bax/Bcl-2 ratio, loss of MMP (mitochondrial membrane potential), induction of cytochrome c release, and activation of caspase 3. In this model, CTN triggers cell death via inactivation of the HSP90 [a 90 kDa isoform of the HSP (heat-shock protein) family proteins]/multichaperone complex and subsequent degradation of Ras and Raf-1, further inhibiting anti-apoptotic processes, such as the Ras→ERK (extracellular-signal-regulated kinase) signal transduction pathway. In addition, CTN causes early developmental injury in mouse ESCs and blastocysts in vitro. Lastly, using an in vivo mouse model, I show that consumption of drinking water containing 10 μM CTN results in blastocyst apoptosis and early embryonic developmental injury. Collectively, these findings show for the first time that CTN induces ROS and mitochondria-dependent apoptotic processes, inhibits Ras→ERK survival signalling via inactivation of the HSP90/multichaperone complex, and causes developmental injury in vivo. PMID:17331071

p53 inhibits CRISPR-Cas9 engineering in human pluripotent stem cells.

PubMed

Ihry, Robert J; Worringer, Kathleen A; Salick, Max R; Frias, Elizabeth; Ho, Daniel; Theriault, Kraig; Kommineni, Sravya; Chen, Julie; Sondey, Marie; Ye, Chaoyang; Randhawa, Ranjit; Kulkarni, Tripti; Yang, Zinger; McAllister, Gregory; Russ, Carsten; Reece-Hoyes, John; Forrester, William; Hoffman, Gregory R; Dolmetsch, Ricardo; Kaykas, Ajamete

2018-06-11

CRISPR/Cas9 has revolutionized our ability to engineer genomes and conduct genome-wide screens in human cells 1-3 . Whereas some cell types are amenable to genome engineering, genomes of human pluripotent stem cells (hPSCs) have been difficult to engineer, with reduced efficiencies relative to tumour cell lines or mouse embryonic stem cells 3-13 . Here, using hPSC lines with stable integration of Cas9 or transient delivery of Cas9-ribonucleoproteins (RNPs), we achieved an average insertion or deletion (indel) efficiency greater than 80%. This high efficiency of indel generation revealed that double-strand breaks (DSBs) induced by Cas9 are toxic and kill most hPSCs. In previous studies, the toxicity of Cas9 in hPSCs was less apparent because of low transfection efficiency and subsequently low DSB induction 3 . The toxic response to DSBs was P53/TP53-dependent, such that the efficiency of precise genome engineering in hPSCs with a wild-type P53 gene was severely reduced. Our results indicate that Cas9 toxicity creates an obstacle to the high-throughput use of CRISPR/Cas9 for genome engineering and screening in hPSCs. Moreover, as hPSCs can acquire P53 mutations 14 , cell replacement therapies using CRISPR/Cas9-enginereed hPSCs should proceed with caution, and such engineered hPSCs should be monitored for P53 function.

Blastocyst-like structures generated solely from stem cells.

PubMed

Rivron, Nicolas C; Frias-Aldeguer, Javier; Vrij, Erik J; Boisset, Jean-Charles; Korving, Jeroen; Vivié, Judith; Truckenmüller, Roman K; van Oudenaarden, Alexander; van Blitterswijk, Clemens A; Geijsen, Niels

2018-05-01

The blastocyst (the early mammalian embryo) forms all embryonic and extra-embryonic tissues, including the placenta. It consists of a spherical thin-walled layer, known as the trophectoderm, that surrounds a fluid-filled cavity sheltering the embryonic cells 1 . From mouse blastocysts, it is possible to derive both trophoblast 2 and embryonic stem-cell lines 3 , which are in vitro analogues of the trophectoderm and embryonic compartments, respectively. Here we report that trophoblast and embryonic stem cells cooperate in vitro to form structures that morphologically and transcriptionally resemble embryonic day 3.5 blastocysts, termed blastoids. Like blastocysts, blastoids form from inductive signals that originate from the inner embryonic cells and drive the development of the outer trophectoderm. The nature and function of these signals have been largely unexplored. Genetically and physically uncoupling the embryonic and trophectoderm compartments, along with single-cell transcriptomics, reveals the extensive inventory of embryonic inductions. We specifically show that the embryonic cells maintain trophoblast proliferation and self-renewal, while fine-tuning trophoblast epithelial morphogenesis in part via a BMP4/Nodal-KLF6 axis. Although blastoids do not support the development of bona fide embryos, we demonstrate that embryonic inductions are crucial to form a trophectoderm state that robustly implants and triggers decidualization in utero. Thus, at this stage, the nascent embryo fuels trophectoderm development and implantation.

Msx-2 expression and glucocorticoid-induced overexpression in embryonic mouse submandibular glands.

PubMed

Jaskoll, T; Luo, W; Snead, M L

1998-01-01

It is well known that the process of branching morphogenesis requires epithelial-mesenchymal interactions. One outstanding model for the study of tissue interactions during branching morphogenesis is the embryonic mouse submandibular gland (SMG). Although it has been clearly demonstrated that the branching pattern is dependent on interactions between the epithelium and the surrounding mesenchyme, little is known about the molecular mechanism underlying the branching process. One group of transcription factors that likely participates in the control of epithelial-mesenchymal inductive interactions are the Msx-class of homeodomain-containing proteins. In this paper, we focus on Msx-2 because its developmental expression is correlated with inductive interactions, suggesting that Msx-2 may play a functional role during cell-cell interactions. We demonstrate the expression of Msx-2 mRNA and protein to be primarily in the branching epithelia with progressive embryonic (E13 to E15) SMG development and, to a lesser extent, in the mesenchyme. We also show that Msx-2 is expressed by embryonic SMG primordia cultured under defined conditions. In addition, to begin to delineate a functional role for Msx-2, we employed an experimental strategy by using exogenous glucocorticoid (CORT) treatment of embryonic SMGs in vitro and in vivo to significantly enhance branching morphogenesis and evaluate the effect of CORT treatment on embryonic SMG Msx-2 expression. A marked increase in Msx-2 transcripts and protein is detected with in vitro and in vivo CORT treatment. Our studies indicate that one mechanism of CORT regulation of salivary gland morphogenesis is likely through the modulation of Msx-2 gene expression.

Gene expression profiles of brain endothelial cells during embryonic development at bulk and single-cell levels.

PubMed

Hupe, Mike; Li, Minerva Xueting; Kneitz, Susanne; Davydova, Daria; Yokota, Chika; Kele-Olovsson, Julianna; Hot, Belma; Stenman, Jan M; Gessler, Manfred

2017-07-11

The blood-brain barrier is a dynamic interface that separates the brain from the circulatory system, and it is formed by highly specialized endothelial cells. To explore the molecular mechanisms defining the unique nature of vascular development and differentiation in the brain, we generated high-resolution gene expression profiles of mouse embryonic brain endothelial cells using translating ribosome affinity purification and single-cell RNA sequencing. We compared the brain vascular translatome with the vascular translatomes of other organs and analyzed the vascular translatomes of the brain at different time points during embryonic development. Because canonical Wnt signaling is implicated in the formation of the blood-brain barrier, we also compared the brain endothelial translatome of wild-type mice with that of mice lacking the transcriptional cofactor β-catenin ( Ctnnb1 ). Our analysis revealed extensive molecular changes during the embryonic development of the brain endothelium. We identified genes encoding brain endothelium-specific transcription factors ( Foxf2 , Foxl2 , Foxq1 , Lef1 , Ppard , Zfp551 , and Zic3 ) that are associated with maturation of the blood-brain barrier and act downstream of the Wnt-β-catenin signaling pathway. Profiling of individual brain endothelial cells revealed substantial heterogeneity in the population. Nevertheless, the high abundance of Foxf2 , Foxq1 , Ppard , or Zic3 transcripts correlated with the increased expression of genes encoding markers of brain endothelial cell differentiation. Expression of Foxf2 and Zic3 in human umbilical vein endothelial cells induced the production of blood-brain barrier differentiation markers. This comprehensive data set may help to improve the engineering of in vitro blood-brain barrier models. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Non-Fouling Biodegradable Poly(ϵ-caprolactone) Nanofibers for Tissue Engineering.

PubMed

Kostina, Nina Yu; Pop-Georgievski, Ognen; Bachmann, Michael; Neykova, Neda; Bruns, Michael; Michálek, Jiří; Bastmeyer, Martin; Rodriguez-Emmenegger, Cesar

2016-01-01

Poly(ϵ-caprolactone) (PCL) nanofibers are very attractive materials for tissue engineering (TE) due to their degradability and structural similarity to the extracellular matrix (ECM). However, upon exposure to biological media, their surface is rapidly fouled by proteins and cells, which may lead to inflammation and foreign body reaction. In this study, an approach for the modification of PCL nanofibers to prevent protein fouling from biological fluids and subsequent cell adhesion is introduced. A biomimetic polydopamine (PDA) layer was deposited on the surface of the PCL nanofibers and four types of antifouling polymer brushes were grown by surface-initiated atom transfer radical polymerization (SI-ATRP) from initiator moieties covalently attached to the PDA layer. Cell adhesion was assessed with mouse embryonic fibroblasts (MEFs). MEFs rapidly adhered and formed cell-matrix adhesions (CMAs) with PCL and PCL-PDA nanofibers. Importantly, the nanofibers modified with antifouling polymer brushes were able to suppress non-specific protein adsorption and thereby cell adhesion. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Embryonic catalase protects against ethanol embryopathies in acatalasemic mice and transgenic human catalase-expressing mice in embryo culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller-Pinsler, Lutfiya; Wells, Peter G., E-mail: pg.wells@utoronto.ca; Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario

Reactive oxygen species (ROS) have been implicated in the mechanism of ethanol (EtOH) teratogenicity, but the protective role of the embryonic antioxidative enzyme catalase is unclear, as embryonic activity is only about 5% of maternal levels. We addressed this question in a whole embryo culture model. C57BL/6 mouse embryos expressing human catalase (hCat) or their wild-type (C57BL/6 WT) controls, and C3Ga.Cg-Cat{sup b}/J catalase-deficient, acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug = GD 1), exposed for 24 h to 2 or 4 mg/mL EtOH or vehicle, and evaluated formore » functional and morphological changes. hCat and C57BL/6 WT vehicle-exposed embryos developed normally, while EtOH was embryopathic in C57BL/6 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed, turning and head length, whereas hCat embryos were protected (p < 0.001). Maternal pretreatment of C57BL/6 WT dams with 50 kU/kg PEG-catalase (PEG-cat) 8 h prior to embryo culture, which increases embryonic catalase activity, blocked all EtOH embryopathies (p < 0.001). Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to WT controls, suggesting that endogenous ROS are embryopathic. EtOH was more embryopathic in aCat embryos than WT controls, evidenced by reduced head length and somite development (p < 0.01), and trends for reduced anterior neuropore closure, turning and crown–rump length. Maternal pretreatment of aCat dams with PEG-Cat blocked all EtOH embryopathies (p < 0.05). These data suggest that embryonic catalase is a determinant of risk for EtOH embryopathies. - Highlights: • Ethanol (EtOH) exposure causes structural embryopathies in embryo culture. • Genetically enhanced catalase (hCat) protects against EtOH embryopathies. • Genetically deficient catalase (aCat) exacerbates EtOH embryopathies. • Embryonic catalase is developmentally important. • EtOH developmental toxicity involves reactive oxygen species formation.« less

Embryonic catalase protects against ethanol embryopathies in acatalasemic mice and transgenic human catalase-expressing mice in embryo culture.

PubMed

Miller-Pinsler, Lutfiya; Wells, Peter G

2015-09-15

Reactive oxygen species (ROS) have been implicated in the mechanism of ethanol (EtOH) teratogenicity, but the protective role of the embryonic antioxidative enzyme catalase is unclear, as embryonic activity is only about 5% of maternal levels. We addressed this question in a whole embryo culture model. C57BL/6 mouse embryos expressing human catalase (hCat) or their wild-type (C57BL/6 WT) controls, and C3Ga.Cg-Cat(b)/J catalase-deficient, acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug=GD 1), exposed for 24h to 2 or 4mg/mL EtOH or vehicle, and evaluated for functional and morphological changes. hCat and C57BL/6 WT vehicle-exposed embryos developed normally, while EtOH was embryopathic in C57BL/6 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed, turning and head length, whereas hCat embryos were protected (p<0.001). Maternal pretreatment of C57BL/6 WT dams with 50kU/kg PEG-catalase (PEG-cat) 8h prior to embryo culture, which increases embryonic catalase activity, blocked all EtOH embryopathies (p<0.001). Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to WT controls, suggesting that endogenous ROS are embryopathic. EtOH was more embryopathic in aCat embryos than WT controls, evidenced by reduced head length and somite development (p<0.01), and trends for reduced anterior neuropore closure, turning and crown-rump length. Maternal pretreatment of aCat dams with PEG-Cat blocked all EtOH embryopathies (p<0.05). These data suggest that embryonic catalase is a determinant of risk for EtOH embryopathies. Copyright © 2015 Elsevier Inc. All rights reserved.

Efficient genome editing of differentiated renal epithelial cells.

PubMed

Hofherr, Alexis; Busch, Tilman; Huber, Nora; Nold, Andreas; Bohn, Albert; Viau, Amandine; Bienaimé, Frank; Kuehn, E Wolfgang; Arnold, Sebastian J; Köttgen, Michael

2017-02-01

Recent advances in genome editing technologies have enabled the rapid and precise manipulation of genomes, including the targeted introduction, alteration, and removal of genomic sequences. However, respective methods have been described mainly in non-differentiated or haploid cell types. Genome editing of well-differentiated renal epithelial cells has been hampered by a range of technological issues, including optimal design, efficient expression of multiple genome editing constructs, attainable mutation rates, and best screening strategies. Here, we present an easily implementable workflow for the rapid generation of targeted heterozygous and homozygous genomic sequence alterations in renal cells using transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeat (CRISPR) system. We demonstrate the versatility of established protocols by generating novel cellular models for studying autosomal dominant polycystic kidney disease (ADPKD). Furthermore, we show that cell culture-validated genetic modifications can be readily applied to mouse embryonic stem cells (mESCs) for the generation of corresponding mouse models. The described procedure for efficient genome editing can be applied to any cell type to study physiological and pathophysiological functions in the context of precisely engineered genotypes.

The effect of matrix composition of 3D constructs on embryonic stem cell differentiation.

PubMed

Battista, Sabrina; Guarnieri, Daniela; Borselli, Cristina; Zeppetelli, Stefania; Borzacchiello, Assunta; Mayol, Laura; Gerbasio, Diego; Keene, Douglas R; Ambrosio, Luigi; Netti, Paolo A

2005-11-01

The use of embryonic stem (ES) cells as unlimited cell source in tissue engineering has ignited the hope of regenerating any kind of tissue in vitro. However, the role of the material in control and guidance of their development and commitment into complex and viable three-dimensional (3D) tissues is still poorly understood. In this work, we investigate the role of material composition and structure on promoting ES cells growth and differentiation, by culturing mouse ES cell-derived embryoid bodies (EBs) in various semi-interpenetrating polymer networks (SIPNs), made of collagen, fibronectin (FN) and laminin (LM). We show that both composition and strength of the supportive matrix play an important role in EBs development. High collagen concentrations inhibit EBs cavitation and hence the following EBs differentiation, by inhibiting apoptosis. The presence of FN in 3D collagen constructs strongly stimulates endothelial cell differentiation and vascularization. Conversely, LM increases the ability of ES cells to differentiate into beating cardiomyocytes. Our data suggest that matrix composition has an important role in EBs development and that it is possible to influence stem cell differentiation toward preferential pattern, by modulating the physical and biochemical properties of the scaffold.

Next-generation mammalian genetics toward organism-level systems biology.

PubMed

Susaki, Etsuo A; Ukai, Hideki; Ueda, Hiroki R

2017-01-01

Organism-level systems biology in mammals aims to identify, analyze, control, and design molecular and cellular networks executing various biological functions in mammals. In particular, system-level identification and analysis of molecular and cellular networks can be accelerated by next-generation mammalian genetics. Mammalian genetics without crossing, where all production and phenotyping studies of genome-edited animals are completed within a single generation drastically reduce the time, space, and effort of conducting the systems research. Next-generation mammalian genetics is based on recent technological advancements in genome editing and developmental engineering. The process begins with introduction of double-strand breaks into genomic DNA by using site-specific endonucleases, which results in highly efficient genome editing in mammalian zygotes or embryonic stem cells. By using nuclease-mediated genome editing in zygotes, or ~100% embryonic stem cell-derived mouse technology, whole-body knock-out and knock-in mice can be produced within a single generation. These emerging technologies allow us to produce multiple knock-out or knock-in strains in high-throughput manner. In this review, we discuss the basic concepts and related technologies as well as current challenges and future opportunities for next-generation mammalian genetics in organism-level systems biology.

Two- and three-input TALE-based AND logic computation in embryonic stem cells.

PubMed

Lienert, Florian; Torella, Joseph P; Chen, Jan-Hung; Norsworthy, Michael; Richardson, Ryan R; Silver, Pamela A

2013-11-01

Biological computing circuits can enhance our ability to control cellular functions and have potential applications in tissue engineering and medical treatments. Transcriptional activator-like effectors (TALEs) represent attractive components of synthetic gene regulatory circuits, as they can be designed de novo to target a given DNA sequence. We here demonstrate that TALEs can perform Boolean logic computation in mammalian cells. Using a split-intein protein-splicing strategy, we show that a functional TALE can be reconstituted from two inactive parts, thus generating two-input AND logic computation. We further demonstrate three-piece intein splicing in mammalian cells and use it to perform three-input AND computation. Using methods for random as well as targeted insertion of these relatively large genetic circuits, we show that TALE-based logic circuits are functional when integrated into the genome of mouse embryonic stem cells. Comparing construct variants in the same genomic context, we modulated the strength of the TALE-responsive promoter to improve the output of these circuits. Our work establishes split TALEs as a tool for building logic computation with the potential of controlling expression of endogenous genes or transgenes in response to a combination of cellular signals.

Dissecting Transcriptional Heterogeneity in Pluripotency: Single Cell Analysis of Mouse Embryonic Stem Cells.

PubMed

Guedes, Ana M V; Henrique, Domingos; Abranches, Elsa

2016-01-01

Mouse Embryonic Stem cells (mESCs) show heterogeneous and dynamic expression of important pluripotency regulatory factors. Single-cell analysis has revealed the existence of cell-to-cell variability in the expression of individual genes in mESCs. Understanding how these heterogeneities are regulated and what their functional consequences are is crucial to obtain a more comprehensive view of the pluripotent state.In this chapter we describe how to analyze transcriptional heterogeneity by monitoring gene expression of Nanog, Oct4, and Sox2, using single-molecule RNA FISH in single mESCs grown in different cell culture medium. We describe in detail all the steps involved in the protocol, from RNA detection to image acquisition and processing, as well as exploratory data analysis.

Cell death and morphogenesis during early mouse development: are they interconnected?

PubMed

Bedzhov, Ivan; Zernicka-Goetz, Magdalena

2015-04-01

Shortly after implantation the embryonic lineage transforms from a coherent ball of cells into polarized cup shaped epithelium. Recently we elucidated a previously unknown apoptosis-independent morphogenic event that reorganizes the pluripotent lineage. Polarization cues from the surrounding basement membrane rearrange the epiblast into a polarized rosette-like structure, where subsequently a central lumen is established. Thus, we provided a new model revising the current concept of apoptosis-dependent epiblast morphogenesis. Cell death however has to be tightly regulated during embryogenesis to ensure developmental success. Here, we follow the stages of early mouse development and take a glimpse at the critical signaling and morphogenic events that determine cells destiny and reshape the embryonic lineage. © 2015 The Authors. Bioessays published by WILEY Periodicals, Inc.

Effects of heavy ion radiation on the brain vascular system and embryonic development

NASA Technical Reports Server (NTRS)

Yang, T. C.; Tobias, C. A.

1984-01-01

The present investigation is concerned with the effects of heavy-ion radiation on the vascular system and the embryonic development, taking into account the results of experiments with neonatal rats and mouse embryos. It is found that heavy ions can be highly effective in producing brain hemorrhages and in causing body deformities. Attention is given to aspects of methodology, the induction of brain hemorrhages by X-rays and heavy ions, and the effect of iron particles on embryonic development. Reported results suggest that high linear energy transfer (LET) heavy ions can be very effective in producing developmental abnormalities.

Epigenetic modulation by TFII-I during embryonic stem cell differentiation.

PubMed

Bayarsaihan, Dashzeveg; Makeyev, Aleksandr V; Enkhmandakh, Badam

2012-10-01

TFII-I transcription factors play an essential role during early vertebrate embryogenesis. Genome-wide mapping studies by ChIP-seq and ChIP-chip revealed that TFII-I primes multiple genomic loci in mouse embryonic stem cells and embryonic tissues. Moreover, many TFII-I-bound regions co-localize with H3K4me3/K27me3 bivalent chromatin within the promoters of lineage-specific genes. This minireview provides a summary of current knowledge regarding the function of TFII-I in epigenetic control of stem cell differentiation. Copyright © 2012 Wiley Periodicals, Inc.

Quantitative and semi-quantitative immunoassay of growth factors and cytokines in the conditioned medium of STO and CF-1 mouse feeder cells

USDA-ARS?s Scientific Manuscript database

Feeder-cells of irradiated mouse fibroblasts are commonly used for, and are generally necessary for, the in vitro maintenance and growth of many fastidious cell types, particularly embryonic stem cells or induced pluripotent stem cells. Quantitative and semi-quantitative immunoassays were performed...

EFFECTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) ON FETAL MOUSE URINARY TRACT EPITHELIUM IN VITRO

EPA Science Inventory

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), produces hydronephrosis by altering the differentiation and proliferation of ureteric epithelial cells in the embryonic C57BL/6N mouse urinary tract. This study examines the effects of TCDD on late gestation fetal urinary tract cells u...

Livestock in biomedical research: history, current status and future prospective.

PubMed

Polejaeva, Irina A; Rutigliano, Heloisa M; Wells, Kevin D

2016-01-01

Livestock models have contributed significantly to biomedical and surgical advances. Their contribution is particularly prominent in the areas of physiology and assisted reproductive technologies, including understanding developmental processes and disorders, from ancient to modern times. Over the past 25 years, biomedical research that traditionally embraced a diverse species approach shifted to a small number of model species (e.g. mice and rats). The initial reasons for focusing the main efforts on the mouse were the availability of murine embryonic stem cells (ESCs) and genome sequence data. This powerful combination allowed for precise manipulation of the mouse genome (knockouts, knockins, transcriptional switches etc.) leading to ground-breaking discoveries on gene functions and regulation, and their role in health and disease. Despite the enormous contribution to biomedical research, mouse models have some major limitations. Their substantial differences compared with humans in body and organ size, lifespan and inbreeding result in pronounced metabolic, physiological and behavioural differences. Comparative studies of strategically chosen domestic species can complement mouse research and yield more rigorous findings. Because genome sequence and gene manipulation tools are now available for farm animals (cattle, pigs, sheep and goats), a larger number of livestock genetically engineered (GE) models will be accessible for biomedical research. This paper discusses the use of cattle, goats, sheep and pigs in biomedical research, provides an overview of transgenic technology in farm animals and highlights some of the beneficial characteristics of large animal models of human disease compared with the mouse. In addition, status and origin of current regulation of GE biomedical models is also reviewed.

Regulatory RNA Key Player in p53-Mediated Apoptosis in Embryonic Stem Cells | Center for Cancer Research

Cancer.gov

Embryonic stem cells (ESCs) must maintain the integrity of their genomes or risk passing potentially deleterious mutations on to numerous tissues. Thus, ESCs have a unique genome surveillance system and easily undergo apoptosis or differentiation when DNA damage is detected. The protein p53 is known to promote differentiation in mouse ESCs (mESCs), but its role in DNA

Interspecies chimera between primate embryonic stem cells and mouse embryos: monkey ESCs engraft into mouse embryos, but not post-implantation fetuses.

PubMed

Simerly, Calvin; McFarland, Dave; Castro, Carlos; Lin, Chih-Cheng; Redinger, Carrie; Jacoby, Ethan; Mich-Basso, Jocelyn; Orwig, Kyle; Mills, Parker; Ahrens, Eric; Navara, Chris; Schatten, Gerald

2011-07-01

Unequivocal evidence for pluripotency in which embryonic stem cells contribute to chimeric offspring has yet to be demonstrated in human or nonhuman primates (NHPs). Here, rhesus and baboons ESCs were investigated in interspecific mouse chimera generated by aggregation or blastocyst injection. Aggregation chimera produced mouse blastocysts with GFP-nhpESCs at the inner cell mass (ICM), and embryo transfers (ETs) generated dimly-fluorescencing abnormal fetuses. Direct injection of GFP-nhpESCs into blastocysts produced normal non-GFP-fluorescencing fetuses. Injected chimera showed >70% loss of GFP-nhpESCs after 21 h culture. Outgrowths of all chimeric blastocysts established distinct but separate mouse- and NHP-ESC colonies. Extensive endogenous autofluorescence compromised anti-GFP detection and PCR analysis did not detect nhpESCs in fetuses. NhpESCs localize to the ICM in chimera and generate pregnancies. Because primate ESCs do not engraft post-implantation, and also because endogenous autofluorescence results in misleading positive signals, interspecific chimera assays for pluripotency with primate stem cells is unreliable with the currently available ESCs. Testing primate ESCs reprogrammed into even more naïve states in these inter-specific chimera assays will be an important future endeavor. Copyright © 2011 Elsevier B.V. All rights reserved.

Knockdown of p53 suppresses Nanog expression in embryonic stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelalim, Essam Mohamed, E-mail: emohamed@qf.org.qa; Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192; Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia

2014-01-10

Highlights: •We investigate the role of p53 in ESCs in the absence of DNA damage. •p53 knockdown suppresses ESC proliferation. •p53 knockdown downregulates Nanog expression. •p53 is essential for mouse ESC self-renewal. -- Abstract: Mouse embryonic stem cells (ESCs) express high levels of cytoplasmic p53. Exposure of mouse ESCs to DNA damage leads to activation of p53, inducing Nanog suppression. In contrast to earlier studies, we recently reported that chemical inhibition of p53 suppresses ESC proliferation. Here, we confirm that p53 signaling is involved in the maintenance of mouse ESC self-renewal. RNA interference-mediated knockdown of p53 induced downregulation of p21more » and defects in ESC proliferation. Furthermore, p53 knockdown resulted in a significant downregulation in Nanog expression at 24 and 48 h post-transfection. p53 knockdown also caused a reduction in Oct4 expression at 48 h post-transfection. Conversely, exposure of ESCs to DNA damage caused a higher reduction of Nanog expression in control siRNA-treated cells than in p53 siRNA-treated cells. These data show that in the absence of DNA damage, p53 is required for the maintenance of mouse ESC self-renewal by regulating Nanog expression.« less

A novel method of mouse ex utero transplantation of hepatic progenitor cells into the fetal liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shikanai, Mima; Asahina, Kinji; Iseki, Sachiko

2009-04-03

Avoiding the limitations of the adult liver niche, transplantation of hepatic stem/progenitor cells into fetal liver is desirable to analyze immature cells in a hepatic developmental environment. Here, we established a new monitor tool for cell fate of hepatic progenitor cells transplanted into the mouse fetal liver by using ex utero surgery. When embryonic day (ED) 14.5 hepatoblasts were injected into the ED14.5 fetal liver, the transplanted cells expressed albumin abundantly or {alpha}-fetoprotein weakly, and contained glycogen in the neonatal liver, indicating that transplanted hepatoblasts can proliferate and differentiate in concord with surrounding recipient parenchymal cells. The transplanted cells becamemore » mature in the liver of 6-week-old mice. Furthermore, this method was applicable to transplantation of hepatoblast-like cells derived from mouse embryonic stem cells. These data indicate that this unique technique will provide a new in vivo experimental system for studying cell fate of hepatic stem/progenitor cells and liver organogenesis.« less

In vivo photoacoustic imaging of mouse embryos

NASA Astrophysics Data System (ADS)

Laufer, Jan; Norris, Francesca; Cleary, Jon; Zhang, Edward; Treeby, Bradley; Cox, Ben; Johnson, Peter; Scambler, Pete; Lythgoe, Mark; Beard, Paul

2012-06-01

The ability to noninvasively image embryonic vascular anatomy in mouse models is an important requirement for characterizing the development of the normal cardiovascular system and malformations in the heart and vascular supply. Photoacoustic imaging, which can provide high resolution non invasive images of the vasculature based upon optical absorption by endogenous hemoglobin, is well suited to this application. In this study, photoacoustic images of mouse embryos were obtained ex vivo and in vivo. The images show intricate details of the embryonic vascular system to depths of up to 10 mm, which allowed whole embryos to be imaged in situ. To achieve this, an all-optical photoacoustic scanner and a novel time reversal image reconstruction algorithm, which provide deep tissue imaging capability while maintaining high spatial resolution and contrast were employed. This technology may find application as an imaging tool for preclinical embryo studies in developmental biology as well as more generally in preclinical and clinical medicine for studying pathologies characterized by changes in the vasculature.

Inhibition of Cell Division and DNA Replication Impair Mouse-Naïve Pluripotency Exit.

PubMed

Waisman, Ariel; Vazquez Echegaray, Camila; Solari, Claudia; Cosentino, María Soledad; Martyn, Iain; Deglincerti, Alessia; Ozair, Mohammad Zeeshan; Ruzo, Albert; Barañao, Lino; Miriuka, Santiago; Brivanlou, Ali; Guberman, Alejandra

2017-09-01

The cell cycle has gained attention as a key determinant for cell fate decisions, but the contribution of DNA replication and mitosis in stem cell differentiation has not been extensively studied. To understand if these processes act as "windows of opportunity" for changes in cell identity, we established synchronized cultures of mouse embryonic stem cells as they exit the ground state of pluripotency. We show that initial transcriptional changes in this transition do not require passage through mitosis and that conversion to primed pluripotency is linked to lineage priming in the G1 phase. Importantly, we demonstrate that impairment of DNA replication severely blocks transcriptional switch to primed pluripotency, even in the absence of p53 activity induced by the DNA damage response. Our data suggest an important role for DNA replication during mouse embryonic stem cell differentiation, which could shed light on why pluripotent cells are only receptive to differentiation signals during G1, that is, before the S phase. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic deletion of the EGFR ligand epigen does not affect mouse embryonic development and tissue homeostasis.

PubMed

Dahlhoff, Maik; Schäfer, Matthias; Wolf, Eckhard; Schneider, Marlon R

2013-02-15

The epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor with manifold functions during development, tissue homeostasis and disease. EGFR activation, the formation of homodimers or heterodimers (with the related ERBB2-4 receptors) and downstream signaling is initiated by the binding of a family of structurally related growth factors, the EGFR ligands. Genetic deletion experiments clarified the biological function of all family members except for the last characterized ligand, epigen. We employed gene targeting in mouse embryonic stem cells to generate mice lacking epigen expression. Loss of epigen did not affect mouse development, fertility, or organ physiology. Quantitative RT-PCR analysis revealed increased expression of betacellulin and EGF in a few organs of epigen-deficient mice, suggesting a functional compensation by these ligands. In conclusion, we completed the genetic analysis of EGFR ligands and show that epigen has non-essential functions or functions that can be compensated by other EGFR ligands during growth and tissue homeostasis. Copyright © 2012 Elsevier Inc. All rights reserved.

A Method to Identify and Isolate Pluripotent Human Stem Cells and Mouse Epiblast Stem Cells Using Lipid Body-Associated Retinyl Ester Fluorescence

PubMed Central

Muthusamy, Thangaselvam; Mukherjee, Odity; Menon, Radhika; Megha, P.B.; Panicker, Mitradas M.

2014-01-01

Summary We describe the use of a characteristic blue fluorescence to identify and isolate pluripotent human embryonic stem cells and human-induced pluripotent stem cells. The blue fluorescence emission (450–500 nm) is readily observed by fluorescence microscopy and correlates with the expression of pluripotency markers (OCT4, SOX2, and NANOG). It allows easy identification and isolation of undifferentiated human pluripotent stem cells, high-throughput fluorescence sorting and subsequent propagation. The fluorescence appears early during somatic reprogramming. We show that the blue fluorescence arises from the sequestration of retinyl esters in cytoplasmic lipid bodies. The retinoid-sequestering lipid bodies are specific to human and mouse pluripotent stem cells of the primed or epiblast-like state and absent in naive mouse embryonic stem cells. Retinol, present in widely used stem cell culture media, is sequestered as retinyl ester specifically by primed pluripotent cells and also can induce the formation of these lipid bodies. PMID:25068130

Development of Mouse Embryonic Stem (ES) Cells: IV Differentiation to Mature T and B Lymphocytes after Implantation of Embryoid Bodies Into Nude Mice

PubMed Central

Mok, Hoyan

1995-01-01

Mouse embryonic stem (ES) cells in culture can differentiate into late stages of many lineage-committed precursor cells. Under appropriate organ-culture conditions, ES cels differentiate into lymphoidlike cells at a stage equivalent to lymphoid cells found in fetal liver. These hematopoietic precursors are located in cup-shaped structures found in some embryoid bodies; we called such embryoid bodies “ES fetuses.” In this study, we have followed the maturation of hematopoietic cells after implantation of ES fetuses into nude mice for 3 weeks. ES-cell-derived lymphoid cells-pre-B cells, mature B cells, and mature T cells were found in all lymphoid organs. Interestingly, there was also an increase of T cells of host origin. Because native nude mouse lack thymus, these T cells might be educated by thymuslike epithelium generated from ES fetuses. Practical applications of this combined in vitro and in vivo system are discussed. PMID:9700357

A new subtype of progenitor cell in the mouse embryonic neocortex

PubMed Central

Wang, Xiaoqun; Tsai, Jin-Wu; LaMonica, Bridget; Kriegstein, Arnold R.

2011-01-01

A hallmark of mammalian brain evolution is cortical expansion, which reflects an increase in the number of cortical neurons established by the progenitor cell subtypes present and the number of their neurogenic divisions. Recent studies have revealed a new class of radial glia-like (oRG) progenitor cells in the human brain, which reside in the outer subventricular zone. Expansion of the subventricular zone and appearance of oRG cells may have been essential evolutionary steps leading from lissencephalic to gyrencephalic neocortex. Here we show that oRG-like progenitor cells are present in the mouse embryonic neocortex. They arise from asymmetric divisions of radial glia and undergo self-renewing asymmetric divisions to generate neurons. Moreover, mouse oRG cells undergo mitotic somal translocation whereby centrosome movement into the basal process during interphase preceeds nuclear translocation. Our finding of oRG cells in the developing rodent brain fills a gap in our understanding of neocortical expansion. PMID:21478886

The embryonic mouse hindbrain as a qualitative and quantitative model for studying the molecular and cellular mechanisms of angiogenesis.

PubMed

Fantin, Alessandro; Vieira, Joaquim M; Plein, Alice; Maden, Charlotte H; Ruhrberg, Christiana

2013-02-01

The mouse embryo hindbrain is a robust and adaptable model for studying sprouting angiogenesis. It permits the spatiotemporal analysis of organ vascularization in normal mice and in mouse strains with genetic mutations that result in late embryonic or perinatal lethality. Unlike postnatal models such as retinal angiogenesis or Matrigel implants, there is no requirement for the breeding of conditional knockout mice. The unique architecture of the hindbrain vasculature allows whole-mount immunolabeling of blood vessels and high-resolution imaging, as well as easy quantification of angiogenic sprouting, network density and vessel caliber. The hindbrain model also permits the visualization of ligand binding to blood vessels in situ and the analysis of blood vessel growth within a natural multicellular microenvironment in which endothelial cells (ECs) interact with non-ECs to refine the 3D organ architecture. The entire procedure, from embryo isolation to imaging and through to results analysis, takes approximately 4 d.

Introduction of a point mutation into the mouse genome by homologous recombination in embryonic stem cells using a replacement type vector with a selectable marker.

PubMed

Rubinstein, M; Japón, M A; Low, M J

1993-06-11

The introduction of small mutations instead of null alleles into the mouse genome has broad applications to the study of protein structure-function relationships and the creation of animal models of human genetic diseases. To test a simple mutational strategy we designed a targeting vector for the mouse proopiomelanocortin (POMC) gene containing a single nucleotide insertion that converts the initial tyrosine codon of beta-endorphin 1-31 to a premature translational termination codon and introduces a unique Hpal endonuclease restriction site. The targeting vector also contains a neo cassette immediately 3' to the last POMC exon and a herpes simplex virus thymidine kinase cassette to allow positive and negative selection. Homologous recombination occurred at a frequency of 1/30 clones of electroporated embryonic stem cells selected in G418 and gancyclovir. 10/11 clones identified initially by a polymerase chain reaction (PCR) strategy had the predicted structure without evidence of concatemer formation by Southern blot analysis. We used a combination of Hpa I digestion of PCR amplified fragments and direct nucleotide sequencing to further confirm that the point mutation was retained in 9/10 clones. The POMC gene was transcriptionally silent in embryonic stem cells and the targeted allele was not activated by the downstream phosphoglycerate kinase-1 promoter that transcribed the neo gene. Under the electroporation conditions used, we have demonstrated that a point mutation can be introduced with high efficiency and precision into the POMC gene using a replacement type vector containing a retained selectable marker without affecting expression of the allele in the embryonic stem cells. A similar strategy may be useful for a wide range of genes.

Introduction of a point mutation into the mouse genome by homologous recombination in embryonic stem cells using a replacement type vector with a selectable marker.

PubMed Central

Rubinstein, M; Japón, M A; Low, M J

1993-01-01

The introduction of small mutations instead of null alleles into the mouse genome has broad applications to the study of protein structure-function relationships and the creation of animal models of human genetic diseases. To test a simple mutational strategy we designed a targeting vector for the mouse proopiomelanocortin (POMC) gene containing a single nucleotide insertion that converts the initial tyrosine codon of beta-endorphin 1-31 to a premature translational termination codon and introduces a unique Hpal endonuclease restriction site. The targeting vector also contains a neo cassette immediately 3' to the last POMC exon and a herpes simplex virus thymidine kinase cassette to allow positive and negative selection. Homologous recombination occurred at a frequency of 1/30 clones of electroporated embryonic stem cells selected in G418 and gancyclovir. 10/11 clones identified initially by a polymerase chain reaction (PCR) strategy had the predicted structure without evidence of concatemer formation by Southern blot analysis. We used a combination of Hpa I digestion of PCR amplified fragments and direct nucleotide sequencing to further confirm that the point mutation was retained in 9/10 clones. The POMC gene was transcriptionally silent in embryonic stem cells and the targeted allele was not activated by the downstream phosphoglycerate kinase-1 promoter that transcribed the neo gene. Under the electroporation conditions used, we have demonstrated that a point mutation can be introduced with high efficiency and precision into the POMC gene using a replacement type vector containing a retained selectable marker without affecting expression of the allele in the embryonic stem cells. A similar strategy may be useful for a wide range of genes. Images PMID:8392702

New gene targets for glucagon-like peptide-1 during embryonic development and in undifferentiated pluripotent cells.

PubMed

Sanz, Carmen; Blázquez, Enrique

2011-09-01

In humans, glucagon-like peptide (GLP-1) functions during adult life as an incretin hormone with anorexigenic and antidiabetogenic properties. Also, the therapeutic potential of GLP-1 in preventing the adipocyte hyperplasia associated with obesity and in bolstering the maintenance of human mesenchymal stem cell (hMSC) stores by promoting the proliferation and cytoprotection of hMSC seems to be relevant. Since these observations suggest a role for GLP-1 during developmental processes, the aim of the present work was to characterize GLP-1 in early development as well as its gene targets in mouse embryonic stem (mES) cells. Mouse embryos E6, E8, and E10.5 and pluripotent mES were used for the inmunodetection of GLP-1 and GLP-1 receptor. Quantitative real-time PCR was used to determine the expression levels of GLP-1R in several tissues from E12.5 mouse embryos. Additionally, GLP-1 gene targets were studied in mES by multiple gene expression analyses. GLP-1 and its receptors were identified in mES and during embryonic development. In pluripotent mES, GLP-1 modified the expression of endodermal, ectodermal, and mesodermal gene markers as well as sonic hedgehog, noggin, members of the fibroblast and hepatic growth factor families, and others involved in pancreatic development. Additionally, GLP-1 promoted the expression of the antiapoptotic gene bcl2 and at the same time reduced proapoptotic caspase genes. Our results indicate that apart from the effects and therapeutic benefits of GLP-1 in adulthood, it may have additional gene targets in mES cells during embryonic life. Furthermore, the pathophysiological implications of GLP-1 imbalance in adulthood may have a counterpart during development.

Dysfunction in gap junction intercellular communication induces aberrant behavior of the inner cell mass and frequent collapses of expanded blastocysts in mouse embryos.

PubMed

Togashi, Kazue; Kumagai, Jin; Sato, Emiko; Shirasawa, Hiromitsu; Shimoda, Yuki; Makino, Kenichi; Sato, Wataru; Kumazawa, Yukiyo; Omori, Yasufumi; Terada, Yukihiro

2015-06-01

We investigated the role of gap junctions (GJs) in embryological differentiation, and observed the morphological behavior of the inner cell mass (ICM) by time-lapse movie observation (TLM) with gap junction inhibitors (GJis). ICR mouse embryos were exposed to two types of GJis in CZB medium: oleamide (0 to 50 μM) and 1-heptanol (0 to 10 mM). We compared the rate of blastocyst formation at embryonic day 4.5 (E4.5) with E5.5. We also observed and evaluated the times from the second cleavage to each embryonic developing stage by TLM. We investigated embryonic distribution of DNA, Nanog protein, and Connexin 43 protein with immunofluorescent staining. In the comparison of E4.5 with E5.5, inhibition of gap junction intercellular communication (GJIC) delayed embryonic blastocyst formation. The times from the second cleavage to blastocyst formation were significantly extended in the GJi-treated embryos (control vs with oleamide, 2224 ± 179 min vs 2354 ± 278 min, p = 0.013). Morphological differences were traced in control versus GJi-treated embryos until the hatching stage. Oleamide induced frequent severe collapses of expanded blastocysts (77.4 % versus 26.3 %, p = 0.0001) and aberrant ICM divisions connected to sticky strands (74.3 % versus 5.3 %, p = 0.0001). Immunofluorescent staining indicated Nanog-positive cells were distributed in each divided ICM. GJIC plays an important role in blastocyst formation, collapses of expanded blastocysts, and the ICM construction in mouse embryos.

Redundant role of protein kinase C delta and epsilon during mouse embryonic development.

PubMed

Carracedo, Sergio; Sacher, Frank; Brandes, Gudrun; Braun, Ursula; Leitges, Michael

2014-01-01

Protein Kinase C delta and epsilon are mediators of important cellular events, such as cell proliferation, migration or apoptosis. The formation of blood vessels, i.e., vasculo- and angiogenesis, is a process where these isoforms have also been shown to participate. However, mice deficient in either Protein Kinase C delta or epsilon are viable and therefore their individual contribution to the formation of the vasculature appeared so far dispensable. In this study, we show that double null mutation of Protein Kinase C delta and epsilon causes embryonic lethality at approximately E9.5. At this stage, whole mount staining of the endothelial marker CD31 in double null embryos revealed defective blood vessel formation. Moreover, culture of double deficient mouse allantois showed impaired endothelial cell organization, and analyses of double deficient embryo sections showed dilated vessels, decreased endothelial-specific adherent junctions, and decreased contact of endothelial cells with mural cells. Protein kinase C delta and epsilon also appeared essential for vascular smooth muscle cell differentiation, since α-smooth muscle actin, a classical marker for vascular smooth muscle cells, was almost undetectable in double deficient embryonic aorta at E9.5. Subsequent qPCR analyses showed decreased VE-cadherin, Vegfr2, Cd31, Cdh2, Ets1, and Fli-1, among other angiogenesis related transcripts in double deficient embryos. Taken together, these data suggest for the first time an in vivo redundant role between members of the novel Protein Kinase C subfamily that allows for mutual compensation during mouse embryonic development, with vasculogenesis/angiogenesis as an obvious common function of these two Protein Kinase Cs. Protein Kinase C delta and epsilon might therefore be useful targets for inhibiting vasculo- and/or angiogenesis.

Merkel Cell Polyomavirus Small T Antigen Induces Cancer and Embryonic Merkel Cell Proliferation in a Transgenic Mouse Model.

PubMed

Shuda, Masahiro; Guastafierro, Anna; Geng, Xuehui; Shuda, Yoko; Ostrowski, Stephen M; Lukianov, Stefan; Jenkins, Frank J; Honda, Kord; Maricich, Stephen M; Moore, Patrick S; Chang, Yuan

2015-01-01

Merkel cell polyomavirus (MCV) causes the majority of human Merkel cell carcinomas (MCC) and encodes a small T (sT) antigen that transforms immortalized rodent fibroblasts in vitro. To develop a mouse model for MCV sT-induced carcinogenesis, we generated transgenic mice with a flox-stop-flox MCV sT sequence homologously recombined at the ROSA locus (ROSAsT), allowing Cre-mediated, conditional MCV sT expression. Standard tamoxifen (TMX) administration to adult UbcCreERT2; ROSAsT mice, in which Cre is ubiquitously expressed, resulted in MCV sT expression in multiple organs that was uniformly lethal within 5 days. Conversely, most adult UbcCreERT2; ROSAsT mice survived low-dose tamoxifen administration but developed ear lobe dermal hyperkeratosis and hypergranulosis. Simultaneous MCV sT expression and conditional homozygous p53 deletion generated multi-focal, poorly-differentiated, highly anaplastic tumors in the spleens and livers of mice after 60 days of TMX treatment. Mouse embryonic fibroblasts from these mice induced to express MCV sT exhibited anchorage-independent cell growth. To examine Merkel cell pathology, MCV sT expression was also induced during mid-embryogenesis in Merkel cells of Atoh1CreERT2/+; ROSAsT mice, which lead to significantly increased Merkel cell numbers in touch domes at late embryonic ages that normalized postnatally. Tamoxifen administration to adult Atoh1CreERT2/+; ROSAsT and Atoh1CreERT2/+; ROSAsT; p53flox/flox mice had no effects on Merkel cell numbers and did not induce tumor formation. Taken together, these results show that MCV sT stimulates progenitor Merkel cell proliferation in embryonic mice and is a bona fide viral oncoprotein that induces full cancer cell transformation in the p53-null setting.

The influence of serum substituents on serum-free Vero cell conditioned culture media manufactured from Dulbecco's modified Eagle medium in mouse embryo culture.

PubMed

Lee, Jong-Seon; Kim, Ju-Hwan; Seo, Young-Seok; Yang, Jung-Bo; Kim, Yong-Il; Kim, Hye-Jin; Lee, Ki-Hwan

2013-09-01

This study was conducted to examine the influences of supplementation of the serum substituents and available period of serum-free Vero cell conditioned media (SF-VCM) manufactured from Dulbecco's modified Eagle medium cultured with Vero cells for in vitro development of mouse preimplantation embryos. A total of 1,099 two-cell embryos collected from imprinting control region mice were cultured in SF-VCM with 10% and 20% human follicular fluid (hFF), serum substitute supplement (SSS), and serum protein substitute (SPS). Development of embryos was observed every 24 hours. Results between different groups were analyzed by chi-square test, and considered statistically significant when P-value was less than 0.05. The rates of embryonic development cultured in SF-VCM supplemented with serum substituents were significantly higher compare with serum-free group (P < 0.05). The rates of embryonic development after 48 hours (morula≤) and 96 hours (blastocyst≤) were significantly higher in 20% SSS and 10% SPS than in 20% hFF supplementation (P < 0.05). And the rates of embryonic development after 96 hours (hatching blastocyst≤) were significantly higher in 10% SPS (94.5%) than in 20% SSS (82.6%) and 20% hFF supplementation (68.5%). The rates of embryonic development according to storage period of the SF-VCM supplemented with 10% SPS showed no significant difference between control, 2 weeks and 4 weeks group. However developmental rate in 6 weeks storage group was significantly lower than other groups. The rate of embryonic development after 96 hours (hatching blastocyst≤) was significantly higher in SF-VCM supplemented with 10% SPS. And storage period of media up to 4 weeks did not affect on embryonic development.

A step-wise approach for analysis of the mouse embryonic heart using 17.6 Tesla MRI

PubMed Central

Gabbay-Benziv, Rinat; Reece, E. Albert; Wang, Fang; Bar-Shir, Amnon; Harman, Chris; Turan, Ozhan M.; Yang, Peixin; Turan, Sifa

2018-01-01

Background The mouse embryo is ideal for studying human cardiac development. However, laboratory discoveries do not easily translate into clinical findings partially because of histological diagnostic techniques that induce artifacts and lack standardization. Aim To present a step-wise approach using 17.6 T MRI, for evaluation of mice embryonic heart and accurate identification of congenital heart defects. Subjects 17.5-embryonic days embryos from low-risk (non-diabetic) and high-risk (diabetic) model dams. Study design Embryos were imaged using 17.6 Tesla MRI. Three-dimensional volumes were analyzed using ImageJ software. Outcome measures Embryonic hearts were evaluated utilizing anatomic landmarks to locate the four-chamber view, the left- and right-outflow tracts, and the arrangement of the great arteries. Inter- and intra-observer agreement were calculated using kappa scores by comparing two researchers’ evaluations independently analyzing all hearts, blinded to the model, on three different, timed occasions. Each evaluated 16 imaging volumes of 16 embryos: 4 embryos from normal dams, and 12 embryos from diabetic dams. Results Inter-observer agreement and reproducibility were 0.779 (95% CI 0.653–0.905) and 0.763 (95% CI 0.605–0.921), respectively. Embryonic hearts were structurally normal in 4/4 and 7/12 embryos from normal and diabetic dams, respectively. Five embryos from diabetic dams had defects: ventricular septal defects (n = 2), transposition of great arteries (n = 2) and Tetralogy of Fallot (n = 1). Both researchers identified all cardiac lesions. Conclusion A step-wise approach for analysis of MRI-derived 3D imaging provides reproducible detailed cardiac evaluation of normal and abnormal mice embryonic hearts. This approach can accurately reveal cardiac structure and, thus, increases the yield of animal model in congenital heart defect research. PMID:27569369

Embryonic domains of the aorta derived from diverse origins exhibit distinct properties that converge into a common phenotype in the adult

PubMed Central

Pfaltzgraff, Elise R.; Shelton, Elaine L.; Galindo, Cristi L.; Nelms, Brian L.; Hooper, Christopher W.; Poole, Stanley D.; Labosky, Patricia A.; Bader, David M.; Reese, Jeff

2014-01-01

Vascular smooth muscle cells (VSMCs) are derived from distinct embryonic origins. Vessels originating from differing smooth muscle cell populations have distinct vascular and pathological properties involving calcification, atherosclerosis, and structural defects such as aneurysm and coarctation. We hypothesized that domains within a single vessel, such as the aorta, vary in phenotype based on embryonic origin. Gene profiling and myographic analyses demonstrated that embryonic ascending and descending aortic domains exhibited distinct phenotypes. In vitro analyses demonstrated that VSMCs from each region were dissimilar in terms of cytoskeletal and migratory properties, and retention of different gene expression patterns. Using the same analysis, we found that these same two domains are indistinguishable in the adult vessel. Our data demonstrate that VSMCs from different embryonic origins are functionally distinct in the embryonic mouse, but converge to assume a common phenotype in the aorta of healthy adults. These findings have fundamental implications for aortic development, function and disease progression. PMID:24508561

Embryonic Cerebrospinal Fluid Increases Neurogenic Activity in the Brain Ventricular-Subventricular Zone of Adult Mice.

PubMed

Alonso, Maria I; Lamus, Francisco; Carnicero, Estela; Moro, Jose A; de la Mano, Anibal; Fernández, Jose M F; Desmond, Mary E; Gato, Angel

2017-01-01

Neurogenesis is a very intensive process during early embryonic brain development, becoming dramatically restricted in the adult brain in terms of extension and intensity. We have previously demonstrated the key role of embryonic cerebrospinal fluid (CSF) in developing brain neurogenic activity. We also showed that cultured adult brain neural stem cells (NSCs) remain competent when responding to the neurogenic influence of embryonic CSF. However, adult CSF loses its neurogenic inductive properties. Here, by means of an organotypic culture of adult mouse brain sections, we show that local administration of embryonic CSF in the subventricular zone (SVZ) niche is able to trigger a neurogenic program in NSCs. This leads to a significant increase in the number of non-differentiated NSCs, and also in the number of new neurons which show normal migration, differentiation and maturation. These new data reveal that embryonic CSF activates adult brain NSCs, supporting the previous idea that it contains key instructive components which could be useful in adult brain neuroregenerative strategies.

Embryonic Cerebrospinal Fluid Increases Neurogenic Activity in the Brain Ventricular-Subventricular Zone of Adult Mice

PubMed Central

Alonso, Maria I.; Lamus, Francisco; Carnicero, Estela; Moro, Jose A.; de la Mano, Anibal; Fernández, Jose M. F.; Desmond, Mary E.; Gato, Angel

2017-01-01

Neurogenesis is a very intensive process during early embryonic brain development, becoming dramatically restricted in the adult brain in terms of extension and intensity. We have previously demonstrated the key role of embryonic cerebrospinal fluid (CSF) in developing brain neurogenic activity. We also showed that cultured adult brain neural stem cells (NSCs) remain competent when responding to the neurogenic influence of embryonic CSF. However, adult CSF loses its neurogenic inductive properties. Here, by means of an organotypic culture of adult mouse brain sections, we show that local administration of embryonic CSF in the subventricular zone (SVZ) niche is able to trigger a neurogenic program in NSCs. This leads to a significant increase in the number of non-differentiated NSCs, and also in the number of new neurons which show normal migration, differentiation and maturation. These new data reveal that embryonic CSF activates adult brain NSCs, supporting the previous idea that it contains key instructive components which could be useful in adult brain neuroregenerative strategies. PMID:29311854

Initiating head development in mouse embryos: integrating signalling and transcriptional activity.

PubMed

Arkell, Ruth M; Tam, Patrick P L

2012-03-01

The generation of an embryonic body plan is the outcome of inductive interactions between the progenitor tissues that underpin their specification, regionalization and morphogenesis. The intercellular signalling activity driving these processes is deployed in a time- and site-specific manner, and the signal strength must be precisely controlled. Receptor and ligand functions are modulated by secreted antagonists to impose a dynamic pattern of globally controlled and locally graded signals onto the tissues of early post-implantation mouse embryo. In response to the WNT, Nodal and Bone Morphogenetic Protein (BMP) signalling cascades, the embryo acquires its body plan, which manifests as differences in the developmental fate of cells located at different positions in the anterior-posterior body axis. The initial formation of the anterior (head) structures in the mouse embryo is critically dependent on the morphogenetic activity emanating from two signalling centres that are juxtaposed with the progenitor tissues of the head. A common property of these centres is that they are the source of antagonistic factors and the hub of transcriptional activities that negatively modulate the function of WNT, Nodal and BMP signalling cascades. These events generate the scaffold of the embryonic head by the early-somite stage of development. Beyond this, additional tissue interactions continue to support the growth, regionalization, differentiation and morphogenesis required for the elaboration of the structure recognizable as the embryonic head.

YAP regulates the expression of Hoxa1 and Hoxc13 in mouse and human oral and skin epithelial tissues.

PubMed

Liu, Ming; Zhao, Shuangyun; Lin, Qingjie; Wang, Xiu-Ping

2015-04-01

Yes-associated protein (YAP) is a Hippo signaling transcriptional coactivator that plays pivotal roles in stem cell proliferation, organ size control, and tumor development. The downstream targets of YAP have been shown to be highly context dependent. In this study, we used the embryonic mouse tooth germ as a tool to search for the downstream targets of YAP in ectoderm-derived tissues. Yap deficiency in the dental epithelium resulted in a small tooth germ with reduced epithelial cell proliferation. We compared the gene expression profiles of embryonic day 14.5 (E14.5) Yap conditional knockout and YAP transgenic mouse tooth germs using transcriptome sequencing (RNA-Seq) and further confirmed the differentially expressed genes using real-time PCR and in situ hybridization. We found that YAP regulates the expression of Hoxa1 and Hoxc13 in oral and dental epithelial tissues as well as in the epidermis of skin during embryonic and adult stages. Sphere formation assay suggested that Hoxa1 and Hoxc13 are functionally involved in YAP-regulated epithelial progenitor cell proliferation, and chromatin immunoprecipitation (ChIP) assay implies that YAP may regulate Hoxa1 and Hoxc13 expression through TEAD transcription factors. These results provide mechanistic insights into abnormal YAP activities in mice and humans. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

RISC-mediated control of selected chromatin regulators stabilizes ground state pluripotency of mouse embryonic stem cells.

PubMed

Pandolfini, Luca; Luzi, Ettore; Bressan, Dario; Ucciferri, Nadia; Bertacchi, Michele; Brandi, Rossella; Rocchiccioli, Silvia; D'Onofrio, Mara; Cremisi, Federico

2016-05-06

Embryonic stem cells are intrinsically unstable and differentiate spontaneously if they are not shielded from external stimuli. Although the nature of such instability is still controversial, growing evidence suggests that protein translation control may play a crucial role. We performed an integrated analysis of RNA and proteins at the transition between naïve embryonic stem cells and cells primed to differentiate. During this transition, mRNAs coding for chromatin regulators are specifically released from translational inhibition mediated by RNA-induced silencing complex (RISC). This suggests that, prior to differentiation, the propensity of embryonic stem cells to change their epigenetic status is hampered by RNA interference. The expression of these chromatin regulators is reinstated following acute inactivation of RISC and it correlates with loss of stemness markers and activation of early cell differentiation markers in treated embryonic stem cells. We propose that RISC-mediated inhibition of specific sets of chromatin regulators is a primary mechanism for preserving embryonic stem cell pluripotency while inhibiting the onset of embryonic developmental programs.

Synuclein impairs trafficking and signaling of BDNF in a mouse model of Parkinson's disease.

PubMed

Fang, Fang; Yang, Wanlin; Florio, Jazmin B; Rockenstein, Edward; Spencer, Brian; Orain, Xavier M; Dong, Stephanie X; Li, Huayan; Chen, Xuqiao; Sung, Kijung; Rissman, Robert A; Masliah, Eliezer; Ding, Jianqing; Wu, Chengbiao

2017-06-20

Recent studies have demonstrated that hyperphosphorylation of tau protein plays a role in neuronal toxicities of α-synuclein (ASYN) in neurodegenerative disease such as familial Alzheimer's disease (AD), dementia with Lewy bodies (DLB) and Parkinson's disease. Using a transgenic mouse model of Parkinson's disease (PD) that expresses GFP-ASYN driven by the PDGF-β promoter, we investigated how accumulation of ASYN impacted axonal function. We found that retrograde axonal trafficking of brain-derived neurotrophic factor (BDNF) in DIV7 cultures of E18 cortical neurons was markedly impaired at the embryonic stage, even though hyperphosphorylation of tau was not detectable in these neurons at this stage. Interestingly, we found that overexpressed ASYN interacted with dynein and induced a significant increase in the activated levels of small Rab GTPases such as Rab5 and Rab7, both key regulators of endocytic processes. Furthermore, expression of ASYN resulted in neuronal atrophy in DIV7 cortical cultures of either from E18 transgenic mouse model or from rat E18 embryos that were transiently transfected with ASYN-GFP for 72 hrs. Our studies suggest that excessive ASYN likely alters endocytic pathways leading to axonal dysfunction in embryonic cortical neurons in PD mouse models.

Chromatin Immunoprecipitation in Early Mouse Embryos.

PubMed

García-González, Estela G; Roque-Ramirez, Bladimir; Palma-Flores, Carlos; Hernández-Hernández, J Manuel

2018-01-01

Epigenetic regulation is achieved at many levels by different factors such as tissue-specific transcription factors, members of the basal transcriptional apparatus, chromatin-binding proteins, and noncoding RNAs. Importantly, chromatin structure dictates the availability of a specific genomic locus for transcriptional activation as well as the efficiency with which transcription can occur. Chromatin immunoprecipitation (ChIP) is a method that allows elucidating gene regulation at the molecular level by assessing if chromatin modifications or proteins are present at a specific locus. Initially, the majority of ChIP experiments were performed on cultured cell lines and more recently this technique has been adapted to a variety of tissues in different model organisms. Using ChIP on mouse embryos, it is possible to document the presence or absence of specific proteins and chromatin modifications at genomic loci in vivo during mammalian development and to get biological meaning from observations made on tissue culture analyses. We describe here a ChIP protocol on freshly isolated mouse embryonic somites for in vivo analysis of muscle specific transcription factor binding on chromatin. This protocol has been easily adapted to other mouse embryonic tissues and has also been successfully scaled up to perform ChIP-Seq.

A microinjection technique for targeting regions of embryonic and neonatal mouse brain in vivo

PubMed Central

Davidson, Steve; Truong, Hai; Nakagawa, Yasushi; Giesler, Glenn J

2009-01-01

A simple pressure injection technique was developed to deliver substances into specific regions of the embryonic and neonatal mouse brain in vivo. The retrograde tracers Fluorogold and cholera toxin B subunit were used to test the validity of the technique. Injected animals survived the duration of transport (24–48 hrs) and then were sacrificed and perfused with fixative. Small injections (≤ 50 nL) were contained within targeted structures of the perinatal brain and labeled distant cells of origin in several model neural pathways. Traced neural pathways in the perinatal mouse were further examined with immunohistochemical methods to test the feasibility of double labeling experiments during development. Several experimental situations in which this technique would be useful are discussed, for example, to label projection neurons in slice or culture preparations of mouse embryos and neonates. The administration of pharmacological or genetic vectors directly into specific neural targets during development should also be feasible. An examination of the form of neural pathways during early stages of life may lead to insights regarding the functional changes that occur during critical periods of development and provide an anatomic basis for some neurodevelopmental disorders. PMID:19840780

The Sox17CreERT2 knock-in mouse line displays spatiotemporal activation of Cre recombinase in distinct Sox17 lineage progenitors.

PubMed

Engert, Silvia; Burtscher, Ingo; Kalali, Behnam; Gerhard, Markus; Lickert, Heiko

2013-11-01

The HMG-box transcription factor Sox17 is essential for endoderm formation, vascular development, and definitive hematopoiesis. To investigate the fate of distinct Sox17-expressing progenitor cells in a spatiotemporal manner, we generated a hormone-inducible CreERT2 knock-in mouse line. By homologous recombination we fused a codon improved, ligand-dependent estrogen receptor Cre recombinase by an intervening viral T2A sequence for co-translational cleavage to the 3' coding region of Sox17. Induction of Cre activity by administration of tamoxifen at defined time points of early mouse development and subsequent genetic lineage tracing confirmed the inducibility and tissue specificity of Cre recombination. Furthermore, Cre activity could be selectively induced in extra-embryonic and embryonic endoderm lineages, the primitive gut tube, and in endothelial cells of the vascular system as well as in the hemogenic endothelium of the dorsal aorta. The Sox17CreERT2 mouse line therefore represents a new tool for genetic lineage tracing in a tissue-specific manner and in addition enables lineage-restricted functional analysis. Copyright © 2013 Wiley Periodicals, Inc.

RBP-Jκ-Dependent Notch Signaling Is Dispensable for Mouse Early Embryonic Development

PubMed Central

Souilhol, Céline; Cormier, Sarah; Tanigaki, Kenji; Babinet, Charles; Cohen-Tannoudji, Michel

2006-01-01

The Notch signaling pathway is an evolutionarily conserved signaling system which has been shown to be essential in cell fate specification and in numerous aspects of embryonic development in all metazoans thus far studied. We recently demonstrated that several components of the Notch signaling pathway, including the four Notch receptors and their five ligands known in mammals, are expressed in mouse oocytes, in mouse preimplantation embryos, or both. This suggested a possible implication of the Notch pathway in the first cell fate specification of the dividing mouse embryo, which results in the formation of the blastocyst. To address this issue directly, we generated zygotes in which both the maternal and the zygotic expression of Rbpsuh, a key element of the core Notch signaling pathway, were abrogated. We find that such zygotes give rise to blastocysts which implant and develop normally. Nevertheless, after gastrulation, these embryos die around midgestation, similarly to Rbpsuh-null mutants. This demonstrates that the RBP-Jκ-dependent pathway, otherwise called the canonical Notch pathway, is dispensable for blastocyst morphogenesis and the establishment of the three germ layers, ectoderm, endoderm, and mesoderm. These results are discussed in the light of recent observations which have challenged this conclusion. PMID:16782866

RBP-Jkappa-dependent notch signaling is dispensable for mouse early embryonic development.

PubMed

Souilhol, Céline; Cormier, Sarah; Tanigaki, Kenji; Babinet, Charles; Cohen-Tannoudji, Michel

2006-07-01

The Notch signaling pathway is an evolutionarily conserved signaling system which has been shown to be essential in cell fate specification and in numerous aspects of embryonic development in all metazoans thus far studied. We recently demonstrated that several components of the Notch signaling pathway, including the four Notch receptors and their five ligands known in mammals, are expressed in mouse oocytes, in mouse preimplantation embryos, or both. This suggested a possible implication of the Notch pathway in the first cell fate specification of the dividing mouse embryo, which results in the formation of the blastocyst. To address this issue directly, we generated zygotes in which both the maternal and the zygotic expression of Rbpsuh, a key element of the core Notch signaling pathway, were abrogated. We find that such zygotes give rise to blastocysts which implant and develop normally. Nevertheless, after gastrulation, these embryos die around midgestation, similarly to Rbpsuh-null mutants. This demonstrates that the RBP-Jkappa-dependent pathway, otherwise called the canonical Notch pathway, is dispensable for blastocyst morphogenesis and the establishment of the three germ layers, ectoderm, endoderm, and mesoderm. These results are discussed in the light of recent observations which have challenged this conclusion.

Cohesin-SA1 deficiency drives aneuploidy and tumourigenesis in mice due to impaired replication of telomeres

PubMed Central

Remeseiro, Silvia; Cuadrado, Ana; Carretero, María; Martínez, Paula; Drosopoulos, William C; Cañamero, Marta; Schildkraut, Carl L; Blasco, María A; Losada, Ana

2012-01-01

Cohesin is a protein complex originally identified for its role in sister chromatid cohesion, although increasing evidence portrays it also as a major organizer of interphase chromatin. Vertebrate cohesin consists of Smc1, Smc3, Rad21/Scc1 and either stromal antigen 1 (SA1) or SA2. To explore the functional specificity of these two versions of cohesin and their relevance for embryonic development and cancer, we generated a mouse model deficient for SA1. Complete ablation of SA1 results in embryonic lethality, while heterozygous animals have shorter lifespan and earlier onset of tumourigenesis. SA1-null mouse embryonic fibroblasts show decreased proliferation and increased aneuploidy as a result of chromosome segregation defects. These defects are not caused by impaired centromeric cohesion, which depends on cohesin-SA2. Instead, they arise from defective telomere replication, which requires cohesion mediated specifically by cohesin-SA1. We propose a novel mechanism for aneuploidy generation that involves impaired telomere replication upon loss of cohesin-SA1, with clear implications in tumourigenesis. PMID:22415365

DNA context represents transcription regulation of the gene in mouse embryonic stem cells

NASA Astrophysics Data System (ADS)

Ha, Misook; Hong, Soondo

2016-04-01

Understanding gene regulatory information in DNA remains a significant challenge in biomedical research. This study presents a computational approach to infer gene regulatory programs from primary DNA sequences. Using DNA around transcription start sites as attributes, our model predicts gene regulation in the gene. We find that H3K27ac around TSS is an informative descriptor of the transcription program in mouse embryonic stem cells. We build a computational model inferring the cell-type-specific H3K27ac signatures in the DNA around TSS. A comparison of embryonic stem cell and liver cell-specific H3K27ac signatures in DNA shows that the H3K27ac signatures in DNA around TSS efficiently distinguish the cell-type specific H3K27ac peaks and the gene regulation. The arrangement of the H3K27ac signatures inferred from the DNA represents the transcription regulation of the gene in mESC. We show that the DNA around transcription start sites is associated with the gene regulatory program by specific interaction with H3K27ac.

Impaired embryonic haematopoiesis yet normal arterial development in the absence of the Notch ligand Jagged1

PubMed Central

Robert-Moreno, Àlex; Guiu, Jordi; Ruiz-Herguido, Cristina; López, M Eugenia; Inglés-Esteve, Julia; Riera, Lluis; Tipping, Alex; Enver, Tariq; Dzierzak, Elaine; Gridley, Thomas; Espinosa, Lluis; Bigas, Anna

2008-01-01

Specific deletion of Notch1 and RBPjκ in the mouse results in abrogation of definitive haematopoiesis concomitant with the loss of arterial identity at embryonic stage. As prior arterial determination is likely to be required for the generation of embryonic haematopoiesis, it is difficult to establish the specific haematopoietic role of Notch in these mutants. By analysing different Notch-ligand-null embryos, we now show that Jagged1 is not required for the establishment of the arterial fate but it is required for the correct execution of the definitive haematopoietic programme, including expression of GATA2 in the dorsal aorta. Moreover, successful haematopoietic rescue of the Jagged1-null AGM cells was obtained by culturing them with Jagged1-expressing stromal cells or by lentiviral-mediated transduction of the GATA2 gene. Taken together, our results indicate that Jagged1-mediated activation of Notch1 is responsible for regulating GATA2 expression in the AGM, which in turn is essential for definitive haematopoiesis in the mouse. PMID:18528438

Mechanical control of notochord morphogenesis by extra-embryonic tissues in mouse embryos.

PubMed

Imuta, Yu; Koyama, Hiroshi; Shi, Dongbo; Eiraku, Mototsugu; Fujimori, Toshihiko; Sasaki, Hiroshi

2014-05-01

Mammalian embryos develop in coordination with extraembryonic tissues, which support embryonic development by implanting embryos into the uterus, supplying nutrition, providing a confined niche, and also providing patterning signals to embryos. Here, we show that in mouse embryos, the expansion of the amniotic cavity (AC), which is formed between embryonic and extraembryonic tissues, provides the mechanical forces required for a type of morphogenetic movement of the notochord known as convergent extension (CE) in which the cells converge to the midline and the tissue elongates along the antero-posterior (AP) axis. The notochord is stretched along the AP axis, and the expansion of the AC is required for CE. Both mathematical modeling and physical simulation showed that a rectangular morphology of the early notochord caused the application of anisotropic force along the AP axis to the notochord through the isotropic expansion of the AC. AC expansion acts upstream of planar cell polarity (PCP) signaling, which regulates CE movement. Our results highlight the importance of extraembryonic tissues as a source of the forces that control the morphogenesis of embryos. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Growth and morphogenesis of embryonic mouse organs on non-coated and extracellular matrix-coated Biopore membrane

NASA Technical Reports Server (NTRS)

Hardman, P.; Klement, B. J.; Spooner, B. S.

1993-01-01

Embryonic mouse salivary glands, pancreata, and kidneys were isolated from embryos of appropriate gestational age by microdissection, and were cultured on Biopore membrane either non-coated or coated with type I collagen or Matrigel. As expected, use of Biopore membrane allowed high quality photomicroscopy of the living organs. In all organs extensive mesenchymal spreading was observed in the presence of type I collagen or Matrigel. However, differences were noted in the effects of extracellular matrix (ECM) coatings on epithelial growth and morphogenesis: salivary glands were minimally affected, pancreas morphogenesis was adversely affected, and kidney growth and branching apparently was enhanced. It is suggested that these differences in behaviour reflect differences in the strength of interactions between the mesenchymal cells and their surrounding endogenous matrix, compared to the exogenous ECM macromolecules. This method will be useful for culture of these and other embryonic organs. In particular, culture of kidney rudiments on ECM-coated Biopore offers a great improvement over previously used methods which do not allow morphogenesis to be followed in vitro.

DNA context represents transcription regulation of the gene in mouse embryonic stem cells.

PubMed

Ha, Misook; Hong, Soondo

2016-04-14

Understanding gene regulatory information in DNA remains a significant challenge in biomedical research. This study presents a computational approach to infer gene regulatory programs from primary DNA sequences. Using DNA around transcription start sites as attributes, our model predicts gene regulation in the gene. We find that H3K27ac around TSS is an informative descriptor of the transcription program in mouse embryonic stem cells. We build a computational model inferring the cell-type-specific H3K27ac signatures in the DNA around TSS. A comparison of embryonic stem cell and liver cell-specific H3K27ac signatures in DNA shows that the H3K27ac signatures in DNA around TSS efficiently distinguish the cell-type specific H3K27ac peaks and the gene regulation. The arrangement of the H3K27ac signatures inferred from the DNA represents the transcription regulation of the gene in mESC. We show that the DNA around transcription start sites is associated with the gene regulatory program by specific interaction with H3K27ac.

Inhibition of Apoptosis Overcomes Stage-Related Compatibility Barriers to Chimera Formation in Mouse Embryos.

PubMed

Masaki, Hideki; Kato-Itoh, Megumi; Takahashi, Yusuke; Umino, Ayumi; Sato, Hideyuki; Ito, Keiichi; Yanagida, Ayaka; Nishimura, Toshinobu; Yamaguchi, Tomoyuki; Hirabayashi, Masumi; Era, Takumi; Loh, Kyle M; Wu, Sean M; Weissman, Irving L; Nakauchi, Hiromitsu

2016-11-03

Cell types more advanced in development than embryonic stem cells, such as EpiSCs, fail to contribute to chimeras when injected into pre-implantation-stage blastocysts, apparently because the injected cells undergo apoptosis. Here we show that transient promotion of cell survival through expression of the anti-apoptotic gene BCL2 enables EpiSCs and Sox17 + endoderm progenitors to integrate into blastocysts and contribute to chimeric embryos. Upon injection into blastocyst, BCL2-expressing EpiSCs contributed to all bodily tissues in chimeric animals while Sox17 + endoderm progenitors specifically contributed in a region-specific fashion to endodermal tissues. In addition, BCL2 expression enabled rat EpiSCs to contribute to mouse embryonic chimeras, thereby forming interspecies chimeras that could survive to adulthood. Our system therefore provides a method to overcome cellular compatibility issues that typically restrict chimera formation. Application of this type of approach could broaden the use of embryonic chimeras, including region-specific chimeras, for basic developmental biology research and regenerative medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

Development of pacemaker properties and rhythmogenic mechanisms in the mouse embryonic respiratory network

PubMed Central

Chevalier, Marc; Toporikova, Natalia; Simmers, John; Thoby-Brisson, Muriel

2016-01-01

Breathing is a vital rhythmic behavior generated by hindbrain neuronal circuitry, including the preBötzinger complex network (preBötC) that controls inspiration. The emergence of preBötC network activity during prenatal development has been described, but little is known regarding inspiratory neurons expressing pacemaker properties at embryonic stages. Here, we combined calcium imaging and electrophysiological recordings in mouse embryo brainstem slices together with computational modeling to reveal the existence of heterogeneous pacemaker oscillatory properties relying on distinct combinations of burst-generating INaP and ICAN conductances. The respective proportion of the different inspiratory pacemaker subtypes changes during prenatal development. Concomitantly, network rhythmogenesis switches from a purely INaP/ICAN-dependent mechanism at E16.5 to a combined pacemaker/network-driven process at E18.5. Our results provide the first description of pacemaker bursting properties in embryonic preBötC neurons and indicate that network rhythmogenesis undergoes important changes during prenatal development through alterations in both circuit properties and the biophysical characteristics of pacemaker neurons. DOI: http://dx.doi.org/10.7554/eLife.16125.001 PMID:27434668

Dax1 and Nanog act in parallel to stabilize mouse embryonic stem cells and induced pluripotency

PubMed Central

Zhang, Junlei; Liu, Gaoke; Ruan, Yan; Wang, Jiali; Zhao, Ke; Wan, Ying; Liu, Bing; Zheng, Hongting; Peng, Tao; Wu, Wei; He, Ping; Hu, Fu-Quan; Jian, Rui

2014-01-01

Nanog expression is heterogeneous and dynamic in embryonic stem cells (ESCs). However, the mechanism for stabilizing pluripotency during the transitions between Nanoghigh and Nanoglow states is not well understood. Here we report that Dax1 acts in parallel with Nanog to regulate mouse ESC (mESCs) identity. Dax1 stable knockdown mESCs are predisposed towards differentiation but do not lose pluripotency, whereas Dax1 overexpression supports LIF-independent self-renewal. Although partially complementary, Dax1 and Nanog function independently and cannot replace one another. They are both required for full reprogramming to induce pluripotency. Importantly, Dax1 is indispensable for self-renewal of Nanoglow mESCs. Moreover, we report that Dax1 prevents extra-embryonic endoderm (ExEn) commitment by directly repressing Gata6 transcription. Dax1 may also mediate inhibition of trophectoderm differentiation independent or as a downstream effector of Oct4. These findings establish a basal role of Dax1 in maintaining pluripotency during the state transition of mESCs and somatic cell reprogramming. PMID:25284313

Promotion of hair follicle development and trichogenesis by Wnt-10b in cultured embryonic skin and in reconstituted skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouji, Yukiteru; Yoshikawa, Masahide; Shiroi, Akira

2006-06-30

We previously showed that Wnt-10b promoted the differentiation of primary skin epithelial cells (MPSEC) toward hair shaft and inner root sheath of the hair follicle (IRS) cells in vitro. In the present study, we found that Wnt-10b promotes the development of hair follicles using a culture of mouse embryonic skin tissue and trichogenesis using a reconstitution experiment with nude mice. Hair follicle development was observed in skin taken from mouse embryos on embryonic day 10.5 following a 2-day culture with recombinant Wnt-10b (rWnt-10b), however, not without rWnt-10b. Brown hair growth was observed at the site of reconstituted skin in Balb/cmore » nude mice where dermal fibroblasts and keratinocytes, derived from C3H/HeN new born mice, were transplanted with Wnt-10b-producing COS cells (Wnt-COS). Without the co-transplantation of Wnt-COS, no hair growth was observed. Our results suggest an important role of Wnt-10b in the initiation of hair follicle development and following trichogenesis.« less

Absence of bundle structure in the neocortex of the reeler mouse at the embryonic stage. Studies by scanning electron microscopic fractography.

PubMed

Mikoshiba, K; Nishimura, Y; Tsukada, Y

The reeler mutant mouse is characterized by a derangement of the cerebral cortical structure due to abnormalities during the migration step at the embryonic stage. We have analyzed both the control and reeler cerebral cortex by means of scanning electron microscopic fractography. In the control cerebral cortex, the bundle formation was composed of fine fibers on which the migrating neuroblasts were attached perpendicular to the pial surface, whereas no bundle formation was observed in the reeler; instead, there was a fine meshwork of fibers surrounding the neuroblasts. The possible role of bundle formation in the normal cerebral cortex and the correlation between the inability of cells to migrate and the absence of bundle formation in the reeler is discussed.

Histone variant H3.3-mediated chromatin remodeling is essential for paternal genome activation in mouse preimplantation embryos.

PubMed

Kong, Qingran; Banaszynski, Laura A; Geng, Fuqiang; Zhang, Xiaolei; Zhang, Jiaming; Zhang, Heng; O'Neill, Claire L; Yan, Peidong; Liu, Zhonghua; Shido, Koji; Palermo, Gianpiero D; Allis, C David; Rafii, Shahin; Rosenwaks, Zev; Wen, Duancheng

2018-03-09

Derepression of chromatin-mediated transcriptional repression of paternal and maternal genomes is considered the first major step that initiates zygotic gene expression after fertilization. The histone variant H3.3 is present in both male and female gametes and is thought to be important for remodeling the paternal and maternal genomes for activation during both fertilization and embryogenesis. However, the underlying mechanisms remain poorly understood. Using our H3.3B-HA-tagged mouse model, engineered to report H3.3 expression in live animals and to distinguish different sources of H3.3 protein in embryos, we show here that sperm-derived H3.3 (sH3.3) protein is removed from the sperm genome shortly after fertilization and extruded from the zygotes via the second polar bodies (PBII) during embryogenesis. We also found that the maternal H3.3 (mH3.3) protein is incorporated into the paternal genome as early as 2 h postfertilization and is detectable in the paternal genome until the morula stage. Knockdown of maternal H3.3 resulted in compromised embryonic development both of fertilized embryos and of androgenetic haploid embryos. Furthermore, we report that mH3.3 depletion in oocytes impairs both activation of the Oct4 pluripotency marker gene and global de novo transcription from the paternal genome important for early embryonic development. Our results suggest that H3.3-mediated paternal chromatin remodeling is essential for the development of preimplantation embryos and the activation of the paternal genome during embryogenesis. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Establishment of Functional Genomics Pipeline in Mouse Epiblast-Like Tissue by Combining Transcriptomic Analysis and Gene Knockdown/Knockin/Knockout, Using RNA Interference and CRISPR/Cas9.

PubMed

Takata, Nozomu; Sakakura, Eriko; Kasukawa, Takeya; Sakuma, Tetsushi; Yamamoto, Takashi; Sasai, Yoshiki

2016-06-01

The epiblast (foremost embryonic ectoderm) generates all three germ layers and therefore has crucial roles in the formation of all mammalian body cells. However, regulation of epiblast gene expression is poorly understood because of the difficulty of manipulating epiblast tissues in vivo. In the present study, using the self-organizing properties of mouse embryonic stem cell (ESC), we generated and characterized epiblast-like tissue in three-dimensional culture. We identified significant genome-wide gene expression changes in this epiblast-like tissue by transcriptomic analysis. In addition, we identified the particular significance of the Erk/Mapk and integrin-linked kinase pathways, and genes related to ectoderm/epithelial formation, using the bioinformatics resources IPA and DAVID. Here, we focused on Fgf5, which ranked in the top 10 among the discovered genes. To develop a functional analysis of Fgf5, we created an efficient method combining CRISPR/Cas9-mediated genome engineering and RNA interference (RNAi). Notably, we show one-step generation of various Fgf5 reporter lines including heterozygous and homozygous knockins (the GET method). For time- and dose-dependent depletion of fgf5 over the course of development, we generated an ESC line harboring Tol2 transposon-mediated integration of an inducible short hairpin RNA interference system (pdiRNAi). Our findings raised the possibility that Fgf/Erk signaling and apicobasal epithelial integrity are important factors in epiblast development. In addition, our methods provide a framework for a broad array of applications in the areas of mammalian genetics and molecular biology to understand development and to improve future therapeutics.

Generation of tooth-periodontium complex structures using high-odontogenic potential dental epithelium derived from mouse embryonic stem cells.

PubMed

Zhang, Yancong; Li, Yongliang; Shi, Ruirui; Zhang, Siqi; Liu, Hao; Zheng, Yunfei; Li, Yan; Cai, Jinglei; Pei, Duanqing; Wei, Shicheng

2017-06-08

A number of studies have shown that tooth-like structures can be regenerated using induced pluripotent stem cells and mouse embryonic stem (mES) cells. However, few studies have reported the regeneration of tooth-periodontium complex structures, which are more suitable for clinical tooth transplantation. We established an optimized approach to induce high-odontogenic potential dental epithelium derived from mES cells by temporally controlling bone morphogenic protein 4 (BMP4) function and regenerated tooth-periodontium complex structures in vivo. First, immunofluorescence and quantitative reverse transcription-polymerase chain reaction were used to identify the watershed of skin and the oral ectoderm. LDN193189 was then used to inhibit the BMP4 receptor around the watershed, followed by the addition of exogenous BMP4 to promote BMP4 function. The generated dental epithelium was confirmed by western blot analysis and immunofluorescence. The generated epithelium was ultimately combined with embryonic day 14.5 mouse mesenchyme and transplanted into the renal capsules of nude mice. After 4 weeks, the tooth-periodontium complex structure was examined by micro-computed tomography (CT) and hematoxylin and eosin (H&E) staining. Our study found that the turning point of oral ectoderm differentiation occurred around day 3 after the embryoid body was transferred to a common culture plate. Ameloblastin-positive dental epithelial cells were detected following the temporal regulation of BMP4. Tooth-periodontium complex structures, which included teeth, a periodontal membrane, and alveolar bone, were formed when this epithelium was combined with mouse dental mesenchyme and transplanted into the renal capsules of nude mice. Micro-CT and H&E staining revealed that the generated tooth-periodontium complex structures shared a similar histological structure with normal mouse teeth. An optimized induction method was established to promote the differentiation of mES cells into dental epithelium by temporally controlling the function of BMP4. A novel tooth-periodontium complex structure was generated using the epithelium.

Effects of deer velvet extract from Formosan sika deer on the embryonic development and anti-oxidative enzymes mRNA expression in mouse embryos.

PubMed

Cheng, Shih-Lin; Lai, Yi-Ling; Lee, Ming-Che; Shen, Perng-Chih; Liu, Shyh-Shyan; Liu, Bing-Tsan

2014-07-03

The deer velvet or its extracts has been widely used in clinic. It has been used in promoting reproductive performances and treating of oxidation and aging process. The aim of this study is to investigate the effects of velvet extract from Formosan sika deer (Formosan sika deer; Cervus nippon taiouanus, FSD) velvet on mouse embryonic development and anti-oxidant ability in vitro. Mouse 4-cells embryos were divided into 16 groups for 72 h in vitro incubation. The embryonic development stages and morphology were evaluated every 12h in experimental period. The quantitative real time PCR was used to measure the CuZn-SOD, GPx and CAT mRNA expression of the blastocysts. The 4-cells embryos of hydrogen peroxide (HP) groups did not continue developing after oxidant stress challenged. The blastocyst developmental rate (90.0-90.4%, P>0.05) and normal morphological rate (84.4-85.1%, P>0.05) of the 1% and 2% DV extract groups were similar to those in the control group (90.7% and 88.8%, respectively). The embryos challenged by HP (5, 10 and 25 μM) and subsequently incubated in mHTF medium with 1% and 2% of deer velvet (DV) extracts were able to continue development; the blastocyst developmental rate of these groups were similar to that in the control group. The relative mRNA expression of the focused anti-oxidative enzymes in the mouse embryos did not significantly differ among the designed DV treatment groups (P>0.05). The FSD velvet extract in adequate concentration could promote anti-oxidative enzymes mRNA expression followed the challenge of hydrogen peroxide, relieve the mouse embryo under oxidative stress, and maintain the blastocyst developmental ability in vitro. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Tracing notochord-derived cells using a Noto-cre mouse: implications for intervertebral disc development.

PubMed

McCann, Matthew R; Tamplin, Owen J; Rossant, Janet; Séguin, Cheryle A

2012-01-01

Back pain related to intervertebral disc degeneration is the most common musculoskeletal problem, with a lifetime prevalence of 82%. The lack of effective treatment for this widespread problem is directly related to our limited understanding of disc development, maintenance and degeneration. The aim of this study was to determine the developmental origins of nucleus pulposus cells within the intervertebral disc using a novel notochord-specific Cre mouse. To trace the fate of notochordal cells within the intervertebral disc, we derived a notochord-specific Cre mouse line by targeting the homeobox gene Noto. Expression of this gene is restricted to the node and the posterior notochord during gastrulation [embryonic day 7.5 (E7.5)-E12.5]. The Noto-cre mice were crossed with a conditional lacZ reporter for visualization of notochord fate in whole-mount embryos. We performed lineage-tracing experiments to examine the contribution of the notochord to spinal development from E12.5 through to skeletally mature mice (9 months). Fate mapping studies demonstrated that, following elongation and formation of the primitive axial skeleton, the notochord gives rise to the nucleus pulposus in fully formed intervertebral discs. Cellular localization of β-galactosidase (encoded by lacZ) and cytokeratin-8 demonstrated that both notochordal cells and chondrocyte-like nucleus pulposus cells are derived from the embryonic notochord. These studies establish conclusively that notochordal cells act as embryonic precursors to all cells found within the nucleus pulposus of the mature intervertebral disc. This suggests that notochordal cells might serve as tissue-specific progenitor cells within the disc and establishes the Noto-cre mouse as a unique tool to interrogate the contribution of notochordal cells to both intervertebral disc development and disc degeneration.

Tracing notochord-derived cells using a Noto-cre mouse: implications for intervertebral disc development

PubMed Central

McCann, Matthew R.; Tamplin, Owen J.; Rossant, Janet; Séguin, Cheryle A.

2012-01-01

SUMMARY Back pain related to intervertebral disc degeneration is the most common musculoskeletal problem, with a lifetime prevalence of 82%. The lack of effective treatment for this widespread problem is directly related to our limited understanding of disc development, maintenance and degeneration. The aim of this study was to determine the developmental origins of nucleus pulposus cells within the intervertebral disc using a novel notochord-specific Cre mouse. To trace the fate of notochordal cells within the intervertebral disc, we derived a notochord-specific Cre mouse line by targeting the homeobox gene Noto. Expression of this gene is restricted to the node and the posterior notochord during gastrulation [embryonic day 7.5 (E7.5)-E12.5]. The Noto-cre mice were crossed with a conditional lacZ reporter for visualization of notochord fate in whole-mount embryos. We performed lineage-tracing experiments to examine the contribution of the notochord to spinal development from E12.5 through to skeletally mature mice (9 months). Fate mapping studies demonstrated that, following elongation and formation of the primitive axial skeleton, the notochord gives rise to the nucleus pulposus in fully formed intervertebral discs. Cellular localization of β-galactosidase (encoded by lacZ) and cytokeratin-8 demonstrated that both notochordal cells and chondrocyte-like nucleus pulposus cells are derived from the embryonic notochord. These studies establish conclusively that notochordal cells act as embryonic precursors to all cells found within the nucleus pulposus of the mature intervertebral disc. This suggests that notochordal cells might serve as tissue-specific progenitor cells within the disc and establishes the Noto-cre mouse as a unique tool to interrogate the contribution of notochordal cells to both intervertebral disc development and disc degeneration. PMID:22028328

Culture of bovine embryos in deproteinized hemodialysate-supplemented media and immature mouse uterine horns.

PubMed

Thuemmel, A E; Gwazdauskas, F C; Canseco, R S; Pearson, R E; Jochle, W

1991-06-01

Bovine morulae (d 6) were used to evaluate embryonic development in a deproteinized hemodialysate, agar embedding, and in the uterus of the immature mouse. Agar-embedded embryos were cultured in Ham's F-10 and 10% steer serum either (treatment 1) immediately after collection or (treatment 2) 24 h after storage in the uterus of the immature mouse. Unembedded embryos were cultured in Ham's F-10 containing (treatment 3) 10% steer serum, (treatment 4) 1% deproteinized hemodialysate CLB1107, or (treatment 5) 1% de-proteinized hemodialysate CLB1107 and 10% steer serum. A greater percentage of the embryos reached the hatched blastocyst stage after culture in treatments 1, 3, 4, and 5 (38.1, 34.6, 28.6, and 21.1%) than in treatment 2 (9.5%) in which embryos were stored in the immature mouse uterus for 24 h prior to in vitro culture. Final development scores for unembedded and agar-embedded embryos cultured in Ham's F-10 (5.5 +/- .3) and 10% steer serum (4.9 +/- .4) were similar and higher than those of embryos cultured in deproteinized hemodialysate CLB1107 (4.2 +/- .4), deproteinized hemodialysate CLB1107 and steer serum (4.2 +/- .4), or immature mouse uteri (3.4 +/- .4). It is concluded that deproteinized hemodialysate supplementation at 1% (vol/vol) failed to enhance embryonic development in vitro. Moreover, bovine morulae were unaffected by agar embedding and were able to develop to a limited extent following short-term storage in the uterus of the immature mouse.

Rho kinase inhibitor Y-27632 and Accutase dramatically increase mouse embryonic stem cell derivation.

PubMed

Zhang, Peng; Wu, Xinglong; Hu, Chunchao; Wang, Pengbo; Li, Xiangyun

2012-01-01

Although it has been 30 yr since the development of derivation methods for mouse embryonic stem (ES) cells, the biology of derivation of ES cells is poorly understood and the efficiency varies dramatically between cell lines. Recently, the Rho kinase inhibitor Y-27632 and the cell dissociation reagent Accutase were reported to significantly inhibit apoptosis of human ES cells during passaging. Therefore, in the current study, C57BL/6×129/Sv mouse blastocysts were used to evaluate the effect of the combination of the two reagents instead of using the conventional 129 line in mouse ES cell derivation. The data presented in this study suggests that the combination of Y-27632 and Accutase significantly increases the efficiency of mouse ES cell derivation; furthermore, no negative side effects were observed with Y-27632 and Accutase treatment. The newly established ES cell lines retain stable karyotype, surface markers expression, formed teratomas, and contributed to viable chimeras and germline transmission by tetraploid complementation assay. In addition, Y-27632 improved embryoid body formation of ES cells. During ES cell microinjection, Y-27632 prevented the formation of dissociation-induced cell blebs and facilitates the selection and the capture of intact cells. The methods presented in this study clearly demonstrate that inhibition of Rho kinase with Y-27632 and Accutase dissociation improve the derivation efficiently and reproducibility of mouse ES cell generation which is essential for reducing variability in the results obtained from different cell lines.

Informing Stem Cell-Based Tendon Tissue Engineering Approaches with Embryonic Tendon Development.

PubMed

Okech, William; Kuo, Catherine K

Adult tendons fail to regenerate normal tissue after injury, and instead form dysfunctional scar tissue with abnormal mechanical properties. Surgical repair with grafts is the current standard to treat injuries, but faces significant limitations including pain and high rates of re-injury. To address this, we aim to regenerate new, normal tendons to replace dysfunctional tendons. A common approach to tendon tissue engineering is to design scaffolds and bioreactors based on adult tendon properties that can direct adult stem cell tenogenesis. Despite significant progress, advances have been limited due, in part, to a need for markers and potent induction cues. Our goal is to develop novel tendon tissue engineering approaches informed by embryonic tendon development. We are characterizing structure-property relationships of embryonic tendon to identify design parameters for three-dimensional scaffolds and bioreactor mechanical loading systems to direct adult stem cell tenogenesis. We will review studies in which we quantified changes in the mechanical and biochemical properties of tendon during embryonic development and elucidated specific mechanisms of functional property elaboration. We then examined the effects of these mechanical and biochemical factors on embryonic tendon cell behavior. Using custom-designed bioreactors, we also examined the effects of dynamic mechanical loading and growth factor treatment on embryonic tendon cells. Our findings have established cues to induce tenogenesis as well as metrics to evaluate differentiation. We finish by discussing how we have evaluated the tenogenic differentiation potential of adult stem cells by comparing their responses to that of embryonic tendon cells in these culture systems.

Biocompatibility of Synthetic Poly(ester urethane)/Polyhedral Oligomeric Silsesquioxane Matrices with Embryonic Stem Cell Proliferation and Differentiation

PubMed Central

Guo, Yan-Lin; Wang, Wenshou; Otaigbe, Joshua U.

2010-01-01

Incorporation of polyhedral oligomeric silsesquioxanes (POSS) into poly (ester urethane)s (PEU) as a building block results in a PEU/POSS hybrid polymer with increased mechanical strength and thermostability. An attractive feature of the new polymer is that it forms a porous matrix when cast in the form of a thin film, making it potentially useful in tissue engineering. In this study, we present detailed microscopic analysis of the PEU/POSS matrix and demonstrate its biocompatibility with cell culture. The PEU/POSS polymer forms a continuous porous matrix with open pores and interconnected grooves. From SEM image analysis, it is calculated that there are about 950 pores per mm2 of the matrix area with pore size ranging from 1 to 15 μm in diameter. The area occupied by the pores represents approximately 7.6 % of matrix area. Using mouse embryonic stem cells (ESCs), we demonstrate that the PEU/POSS matrix provides excellent support for cell proliferation and differentiation. Under the cell culture condition optimized to maintain self-renewal, ESCs grown on a PEU/POSS matrix exhibit undifferentiated morphology, express pluripotency markers, and have similar growth rate to cells grown on gelatin. When induced for differentiation, ESCs underwent dramatic morphological change, characterized by the loss of clonogenecity and increased cell size with well-expanded cytoskeleton networks. Differentiated cells are able to form a continuous monolayer that is closely embedded on the matrix. The excellent compatibility between the PEU/POSS matrix and ESC proliferation/differentiation demonstrates the potential of using PEU/POSS polymers in future ESC-based tissue engineering. PMID:20213627

Jmjd5 functions as a regulator of p53 signaling during mouse embryogenesis.

PubMed

Ishimura, Akihiko; Terashima, Minoru; Tange, Shoichiro; Suzuki, Takeshi

2016-03-01

Genetic studies have shown that aberrant activation of p53 signaling leads to embryonic lethality. Maintenance of a fine balance of the p53 protein level is critical for normal development. Previously, we have reported that Jmjd5, a member of the Jumonji C (JmjC) family, regulates embryonic cell proliferation through the control of Cdkn1a expression. Since Cdkn1a is the representative p53-regulated gene, we have examined whether the expression of other p53 target genes is coincidentally upregulated with Cdkn1a in Jmjd5-deficient embryos. The expression of a subset of p53-regulated genes was increased in both Jmjd5 hypomorphic mouse embryonic fibroblasts (MEFs) and Jmjd5-deficient embryos at embryonic day 8.25 without the induced expression of Trp53. Intercrossing of Jmjd5-deficient mice with Trp53 knockout mice showed that the growth defect of Jmjd5 mutant cells was significantly recovered under a Trp53 null genetic background. Chromatin immunoprecipitation analysis in Jmjd5 hypomorphic MEFs indicated the increased recruitment of p53 at several p53 target gene loci, such as Cdkn1a, Pmaip1, and Mdm2. These results suggest that Jmjd5 is involved in the transcriptional regulation of a subset of p53-regulated genes, possibly through the control of p53 recruitment at the gene loci. In Jmjd5-deficient embryos, the enhanced recruitment of p53 might result in the abnormal activation of p53 signaling leading to embryonic lethality.

Intermolecular Interactions of Homologs of Germ Plasm Components in Mammalian Germ Cells

PubMed Central

Fox, Mark S.; Clark, Amander T.; El Majdoubi, Mohammed; Vigne, Jean-Louis; Urano, Jun; Hostetler, Chris E.; Griswold, Michael D.; Weiner, Richard I.; Pera, Renee A. Reijo

2007-01-01

In some species such as flies, worms, frogs, and fish the key to forming and maintaining early germ cell populations is the assembly of germ plasm, microscopically-distinct egg cytoplasm that is rich in RNAs, RNA-binding proteins and ribosomes. Cells which inherit germ plasm are destined for the germ cell lineage. In contrast, in mammals, germ cells are formed and maintained later in development as a result of inductive signaling from one embryonic cell type to another. Research advances, using complementary approaches, including identification of key signaling factors that act during the initial stages of germ cell development, differentiation of germ cells in vitro from mouse and human embryonic stem cells and the demonstration, that homologs of germ plasm components are conserved in mammals, have shed light on key elements in the early development of mammalian germ cells. Here, we use FRET (Fluorescence Resonance Energy Transfer) to demonstrate that living mammalian germ cells possess specific RNA/protein complexes that contain germ plasm homologs, beginning in the earliest stages of development examined. Moreover, we demonstrate that although both human and mouse germ cells and embryonic stem cells express the same proteins, germ cell specific protein/protein interactions distinguish germ cells from precursor embryonic stem cells in vitro; interactions also determine sub-cellular localization of complex components. Finally, we suggest that assembly of similar protein complexes may be central to differentiation of diverse cell lineages and provide useful diagnostic tools for isolation of specific cell types from the assorted types differentiated from embryonic stem cells. PMID:16996493

MRG15 Regulates Embryonic Development and Cell Proliferation

PubMed Central

Tominaga, Kaoru; Kirtane, Bhakti; Jackson, James G.; Ikeno, Yuji; Ikeda, Takayoshi; Hawks, Christina; Smith, James R.; Matzuk, Martin M.; Pereira-Smith, Olivia M.

2005-01-01

MRG15 is a highly conserved protein, and orthologs exist in organisms from yeast to humans. MRG15 associates with at least two nucleoprotein complexes that include histone acetyltransferases and/or histone deacetylases, suggesting it is involved in chromatin remodeling. To study the role of MRG15 in vivo, we generated knockout mice and determined that the phenotype is embryonic lethal, with embryos and the few stillborn pups exhibiting developmental delay. Immunohistochemical analysis indicates that apoptosis in Mrg15−/− embryos is not increased compared with wild-type littermates. However, the number of proliferating cells is significantly reduced in various tissues of the smaller null embryos compared with control littermates. Cell proliferation defects are also observed in Mrg15−/− mouse embryonic fibroblasts. The hearts of the Mrg15−/− embryos exhibit some features of hypertrophic cardiomyopathy. The increase in size of the cardiomyocytes is most likely a response to decreased growth of the cells. Mrg15−/− embryos appeared pale, and microarray analysis revealed that α-globin gene expression was decreased in null versus wild-type embryos. We determined by chromatin immunoprecipitation that MRG15 was recruited to the α-globin promoter during dimethyl sulfoxide-induced mouse erythroleukemia cell differentiation. These findings demonstrate that MRG15 has an essential role in embryonic development via chromatin remodeling and transcriptional regulation. PMID:15798182

2,3,7,8-Tetrachlorodibenzo-p-dioxin specifically reduces mRNA for the mineralization-related dentin sialophosphoprotein in cultured mouse embryonic molar teeth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiukkonen, Anu; Sahlberg, Carin; Lukinmaa, Pirjo-Liisa

2006-11-01

Previous studies show that the most toxic dioxin congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), interferes with mineralization of the dental matrices in developing mouse and rat teeth. Culture of mouse embryonic molar teeth with TCDD leads to the failure of enamel to be deposited and dentin to undergo mineralization. Lactationally exposed rats show defectively matured enamel and retardation of dentin mineralization. To see if the impaired mineralization is associated with changes in the expression of dentin sialophosphoprotein (Dspp), Bono1 and/or matrix metalloproteinase-20 (MMP-20), thought to be involved in mineralization of the dental hard tissues, we cultured mouse (NMRI) E18 mandibular molars for 3,more » 5 or 7 days and exposed them to 1 {mu}M TCDD after 2 days of culture. As detected by in situ hybridization of tissue sections, localization and intensity of Bono1 and MMP-20 expression showed no definite difference between the control and exposed tooth explants, suggesting that TCDD does not affect their expression. On the contrary, TCDD reduced or prevented the expression of Dspp in secretory odontoblasts and decreased it in presecretory ameloblasts. The results suggest that the retardation of dentin mineralization by TCDD in mouse molar teeth involves specific interference with Dspp expression.« less

The Growth Factor Progranulin Binds to TNF Receptors and Is Therapeutic Against Inflammatory Arthritis in Mice

PubMed Central

Tang, Wei; Lu, Yi; Tian, Qing-Yun; Zhang, Yan; Guo, Feng-Jin; Liu, Guang-Yi; Syed, Nabeel Muzaffar; Lai, Yongjie; Lin, Edward Alan; Kong, Li; Su, Jeffrey; Yin, Fangfang; Ding, Ai-Hao; Zanin-Zhorov, Alexandra; Dustin, Michael L.; Tao, Jian; Craft, Joseph; Yin, Zhinan; Feng, Jian Q.; Abramson, Steven B.; Yu, Xiu-Ping; Liu, Chuan-ju

2011-01-01

The growth factor progranulin (PGRN) has been implicated in embryonic development, tissue repair, tumorigenesis, and inflammation, but its receptors remain unidentified. We report that PGRN bound directly to tumor necrosis factor receptors (TNFR), and disturbed the TNFα/TNFR interaction. PGRN-deficient mice were susceptible to collagen-induced arthritis, and administration of PGRN reversed inflammatory arthritis. Atsttrin, an engineered protein composed of three PGRN fragments, exhibited selective TNFR binding. PGRN and Atsttrin prevented inflammation in multiple arthritis mouse models and inhibited TNFα-activated intracellular signaling. Collectively, these findings demonstrate that PGRN is a ligand of TNFR, an antagonist of TNFα signaling and plays a critical role in the pathogenesis of inflammatory arthritis in mice. They also suggest new potential therapeutic interventions for various TNFα-mediated pathologies and conditions, including rheumatoid arthritis. PMID:21393509

An integrated miRNA functional screening and target validation method for organ morphogenesis.

PubMed

Rebustini, Ivan T; Vlahos, Maryann; Packer, Trevor; Kukuruzinska, Maria A; Maas, Richard L

2016-03-16

The relative ease of identifying microRNAs and their increasing recognition as important regulators of organogenesis motivate the development of methods to efficiently assess microRNA function during organ morphogenesis. In this context, embryonic organ explants provide a reliable and reproducible system that recapitulates some of the important early morphogenetic processes during organ development. Here we present a method to target microRNA function in explanted mouse embryonic organs. Our method combines the use of peptide-based nanoparticles to transfect specific microRNA inhibitors or activators into embryonic organ explants, with a microRNA pulldown assay that allows direct identification of microRNA targets. This method provides effective assessment of microRNA function during organ morphogenesis, allows prioritization of multiple microRNAs in parallel for subsequent genetic approaches, and can be applied to a variety of embryonic organs.

HCN4-Overexpressing Mouse Embryonic Stem Cell-Derived Cardiomyocytes Generate a New Rapid Rhythm in Rats with Bradycardia.

PubMed

Saito, Yukihiro; Nakamura, Kazufumi; Yoshida, Masashi; Sugiyama, Hiroki; Takano, Makoto; Nagase, Satoshi; Morita, Hiroshi; Kusano, Kengo F; Ito, Hiroshi

2018-05-30

A biological pacemaker is expected to solve the persisting problems of an artificial cardiac pacemaker including short battery life, lead breaks, infection, and electromagnetic interference. We previously reported HCN4 overexpression enhances pacemaking ability of mouse embryonic stem cell-derived cardiomyocytes (mESC-CMs) in vitro. However, the effect of these cells on bradycardia in vivo has remained unclear. Therefore, we transplanted HCN4-overexpressing mESC-CMs into bradycardia model animals and investigated whether they could function as a biological pacemaker. The rabbit Hcn4 gene was transfected into mouse embryonic stem cells and induced HCN4-overexpressing mESC-CMs. Non-cardiomyocytes were removed under serum/glucose-free and lactate-supplemented conditions. Cardiac balls containing 5 × 10 3 mESC-CMs were made by using the hanging drop method. One hundred cardiac balls were injected into the left ventricular free wall of complete atrioventricular block (CAVB) model rats. Heart beats were evaluated using an implantable telemetry system 7 to 30 days after cell transplantation. The result showed that ectopic ventricular beats that were faster than the intrinsic escape rhythm were often observed in CAVB model rats transplanted with HCN4-overexpressing mESC-CMs. On the other hand, the rats transplanted with non-overexpressing mESC-CMs showed sporadic single premature ventricular contraction but not sustained ectopic ventricular rhythms. These results indicated that HCN4-overexpressing mESC-CMs produce rapid ectopic ventricular rhythms as a biological pacemaker.

A novel fish collagen scaffold as dural substitute.

PubMed

Li, Qing; Mu, Lanlan; Zhang, Fenghua; Sun, Yue; Chen, Quan; Xie, Cuicui; Wang, Hongmei

2017-11-01

The novel fish collagen scaffolds were prepared by lyophilization. The collagen sponges and chitosan were chemically cross-linked with the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a cross-linking agent by pressing in one special mould. The collagen scaffolds were analyzed by scanning electron microscopy (SEM) and mechanical property, and the in vitro collagenase degradation was tested. The results revealed that the scaffold has a suitable porosity, elasticity and prevent fluid leakage, suggesting potential applications in the tissue-engineered. In vitro collagenase degradation demonstrated that the collagen cross-linking with EDC by pressing played an important role in their resistance to biodegradation. Moreover, the scaffold proved excellent biocompatibility for the activity and proliferation of mouse embryonic fibroblasts cells (MEFs) in vitro. The rabbit dural defect model demonstrated that the scaffolds could prevent brain tissue adhesion, which reduce the opportunity of inflammation, facilitate the growth of fibroblasts and enhance the tissue regeneration and healing. The novel fish collagen scaffold as dural substitute, demonstrate a capability for using in the field of tissue engineering. Copyright © 2017. Published by Elsevier B.V.

Identification of a small molecule that facilitates the differentiation of human iPSCs/ESCs and mouse embryonic pancreatic explants into pancreatic endocrine cells.

PubMed

Kondo, Yasushi; Toyoda, Taro; Ito, Ryo; Funato, Michinori; Hosokawa, Yoshiya; Matsui, Satoshi; Sudo, Tomomi; Nakamura, Masahiro; Okada, Chihiro; Zhuang, Xiaotong; Watanabe, Akira; Ohta, Akira; Inagaki, Nobuya; Osafune, Kenji

2017-08-01

Pancreatic beta-like cells generated from human induced pluripotent stem cells (hiPSCs) or human embryonic stem cells (hESCs) offer an appealing donor tissue source. However, differentiation protocols that mainly use growth factors are costly. Therefore, in this study, we aimed to establish efficient differentiation protocols to change hiPSCs/hESCs to insulin (INS) + cells using novel small-molecule inducers. We screened small molecules that increased the induction rate of INS + cells from hESC-derived pancreatic and duodenal homeobox 1 (PDX1) + pancreatic progenitor cells. The differentiation protocol to generate INS + cells from hiPSCs/hESCs was optimised using hit compounds, and INS + cells induced with the compounds were characterised for their in vitro and in vivo functions. The inducing activity of the hit compounds was also examined using mouse embryonic pancreatic tissues in an explant culture system. Finally, RNA sequencing analyses were performed on the INS + cells to elucidate the mechanisms of action by which the hit compounds induced pancreatic endocrine differentiation. One hit compound, sodium cromoglicate (SCG), was identified out of approximately 1250 small molecules screened. When SCG was combined with a previously described protocol, the induction rate of INS + cells increased from a mean ± SD of 5.9 ± 1.5% (n = 3) to 16.5 ± 2.1% (n = 3). SCG induced neurogenin 3-positive cells at a mean ± SD of 32.6 ± 4.6% (n = 3) compared with 14.2 ± 3.6% (n = 3) for control treatment without SCG, resulting in an increased generation of endocrine cells including insulin-producing cells. Similar induction by SCG was confirmed using mouse embryonic pancreatic explants. We also confirmed that the mechanisms of action by which SCG induced pancreatic endocrine differentiation included the inhibition of bone morphogenetic protein 4 signalling. SCG improves the generation of pancreatic endocrine cells from multiple hiPSC/hESC lines and mouse embryonic pancreatic explants by facilitating the differentiation of endocrine precursors. This discovery will contribute to elucidating the mechanisms of pancreatic endocrine development and facilitate cost-effective generation of INS + cells from hiPSCs/hESCs. The RNA sequencing data generated during the current study are available in the Gene Expression Omnibus ( www.ncbi.nlm.nih.gov/geo ) with series accession number GSE89973.

Differentiation and upregulation of heat shock protein 70 induced by a subset of histone deacetylase inhibitors in mouse and human embryonic stem cells.

PubMed

Park, Jeong-A; Kim, Young-Eun; Seok, Hyun-Jeong; Park, Woo-Youn; Kwon, Hyung-Joo; Lee, Younghee

2011-03-01

Inhibiting histone deacetylase (HDAC) activity modulates the epigenetic status of cells, resulting in an alteration of gene expression and cellular function. Here, we investigated the effects of HDAC inhibitors on mouse embryonic stem (ES) cells. The HDAC inhibitors trichostatin A, suberoylanilide hydroxamic acid, sodium butyrate, and valproic acid induced early differentiation of mouse ES cells and triggered induction of heatshock protein (HSP)70. In contrast, class III HDAC inhibitors failed to induce differentiation or HSP70 expression. Transcriptional upregulation of HSP70 was confirmed by mRNA expression analysis, an inhibitor study, and chromatin immunoprecipitation. HSP70 induction was dependent on the SAPK/ JNK, p38, and PI3K/Akt pathways. Differentiation and induction of HSP70 by a subset of HDAC inhibitors was also examined in human ES cells, which suggests that the phenomenon generally occurs in ES cells. A better understanding of the effects of HDAC inhibitors may give more insight into their application in stem cell biology.

The RNA-Editing Enzyme ADAR1 Controls Innate Immune Responses to RNA

PubMed Central

Mannion, Niamh M.; Greenwood, Sam M.; Young, Robert; Cox, Sarah; Brindle, James; Read, David; Nellåker, Christoffer; Vesely, Cornelia; Ponting, Chris P.; McLaughlin, Paul J.; Jantsch, Michael F.; Dorin, Julia; Adams, Ian R.; Scadden, A.D.J.; Öhman, Marie; Keegan, Liam P.; O’Connell, Mary A.

2014-01-01

Summary The ADAR RNA-editing enzymes deaminate adenosine bases to inosines in cellular RNAs. Aberrant interferon expression occurs in patients in whom ADAR1 mutations cause Aicardi-Goutières syndrome (AGS) or dystonia arising from striatal neurodegeneration. Adar1 mutant mouse embryos show aberrant interferon induction and die by embryonic day E12.5. We demonstrate that Adar1 embryonic lethality is rescued to live birth in Adar1; Mavs double mutants in which the antiviral interferon induction response to cytoplasmic double-stranded RNA (dsRNA) is prevented. Aberrant immune responses in Adar1 mutant mouse embryo fibroblasts are dramatically reduced by restoring the expression of editing-active cytoplasmic ADARs. We propose that inosine in cellular RNA inhibits antiviral inflammatory and interferon responses by altering RLR interactions. Transfecting dsRNA oligonucleotides containing inosine-uracil base pairs into Adar1 mutant mouse embryo fibroblasts reduces the aberrant innate immune response. ADAR1 mutations causing AGS affect the activity of the interferon-inducible cytoplasmic isoform more severely than the nuclear isoform. PMID:25456137

RNAi-Dependent and Independent Control of LINE1 Accumulation and Mobility in Mouse Embryonic Stem Cells

PubMed Central

Ciaudo, Constance; Jay, Florence; Okamoto, Ikuhiro; Chen, Chong-Jian; Sarazin, Alexis; Servant, Nicolas; Barillot, Emmanuel; Heard, Edith; Voinnet, Olivier

2013-01-01

In most mouse tissues, long-interspersed elements-1 (L1s) are silenced via methylation of their 5′-untranslated regions (5′-UTR). A gradual loss-of-methylation in pre-implantation embryos coincides with L1 retrotransposition in blastocysts, generating potentially harmful mutations. Here, we show that Dicer- and Ago2-dependent RNAi restricts L1 accumulation and retrotransposition in undifferentiated mouse embryonic stem cells (mESCs), derived from blastocysts. RNAi correlates with production of Dicer-dependent 22-nt small RNAs mapping to overlapping sense/antisense transcripts produced from the L1 5′-UTR. However, RNA-surveillance pathways simultaneously degrade these transcripts and, consequently, confound the anti-L1 RNAi response. In Dicer−/− mESC complementation experiments involving ectopic Dicer expression, L1 silencing was rescued in cells in which microRNAs remained strongly depleted. Furthermore, these cells proliferated and differentiated normally, unlike their non-complemented counterparts. These results shed new light on L1 biology, uncover defensive, in addition to regulatory roles for RNAi, and raise questions on the differentiation defects of Dicer−/− mESCs. PMID:24244175

Inhibition of chondroitin sulfate glycosaminoglycans incorporation affected odontoblast differentiation in cultured embryonic mouse molars.

PubMed

Liu, Lipei; Chen, Weiting; Li, Lefeng; Xu, Fangfang; Jiang, Beizhan

2017-12-01

Chondroitin sulfate proteoglycan (CSPG) is an important component of extracellular matrix (ECM), it is composed of a core protein and one or more chondroitin sulfate glycosaminoglycan side chains (CS-GAGs). To investigate the roles of its CS-GAGs in dentinogenesis, the mouse mandibular first molar tooth germs at early bell stage were cultivated with or without β-xyloside. As expected, the CS-GAGs were inhibited on their incorporation to CSPGs by β-xyloside, accompanied by the change of morphology of the cultured tooth germs. The histological results and the transmission electron microscopy (TEM) investigation indicated that β-xyloside exhibited obvious inhibiting effects on odontoblasts differentiation compared with the control group. Meanwhile the results of immunohistochemistry, in situ hybridization and quantitative RT-PCR for type I collagen, dentin matrix acidic phosphoprotein 1 and dentin sialophosphoprotein, the products of differentiated odontoblasts, further proved that odontoblasts differentiation was inhibited. Collagen fibers detected in TEM decreased and arranged in disorder as well. Thus we conclude that the inhibition of CS-GAGs incorporation to CSPGs can affect odontoblast differentiation in cultured embryonic mouse molars.

Mouse mutants from chemically mutagenized embryonic stem cells

PubMed Central

Munroe, Robert J.; Bergstrom, Rebecca A.; Zheng, Qing Yin; Libby, Brian; Smith, Richard; John, Simon W.M.; Schimenti, Kerry J.; Browning, Victoria L.; Schimenti, John C.

2010-01-01

The drive to characterize functions of human genes on a global scale has stimulated interest in large-scale generation of mouse mutants. Conventional germ-cell mutagenesis with N-ethyl-N-nitrosourea (ENU) is compromised by an inability to monitor mutation efficiency, strain1 and interlocus2 variation in mutation induction, and extensive husbandry requirements. To overcome these obstacles and develop new methods for generating mouse mutants, we devised protocols to generate germline chi-maeric mice from embryonic stem (ES) cells heavily mutagenized with ethylmethanesulphonate (EMS). Germline chimaeras were derived from cultures that underwent a mutation rate of up to 1 in 1,200 at the Hprt locus (encoding hypoxanthine guanine phosphoribosyl transferase). The spectrum of mutations induced by EMS and the frameshift mutagen ICR191 was consistent with that observed in other mammalian cells. Chimaeras derived from ES cells treated with EMS transmitted mutations affecting several processes, including limb development, hair growth, hearing and gametogenesis. This technology affords several advantages over traditional mutagenesis, including the ability to conduct shortened breeding schemes and to screen for mutant phenotypes directly in ES cells or their differentiated derivatives. PMID:10700192

Polycomb-like 2 Associates with PRC2 and Regulates Transcriptional Networks during Mouse Embryonic Stem Cell Self-Renewal and Differentiation

PubMed Central

Walker, Emily; Chang, Wing Y.; Hunkapiller, Julie; Cagney, Gerard; Garcha, Kamal; Torchia, Joseph; Krogan, Nevan J.; Reiter, Jeremy F.; Stanford, William L.

2010-01-01

Summary Polycomb group (PcG) proteins are conserved epigenetic transcriptional repressors that control numerous developmental gene expression programs and have recently been implicated in modulating embryonic stem cell (ESC) fate. We identified the PcG protein PCL2 (polycomb-like 2) in a genome-wide screen for regulators of self-renewal and pluripotency and predicted that it would play an important role in mouse ESC fate determination. Using multiple biochemical strategies, we provide evidence that PCL2 is a Polycomb Repressive Complex 2 (PRC2)-associated protein in mouse ESCs. Knockdown of Pcl2 in ESCs resulted in heightened self-renewal characteristics, defects in differentiation and altered patterns of histone methylation. Integration of global gene expression and promoter occupancy analyses allowed us to identify PCL2 and PRC2 transcriptional targets and draft regulatory networks. We describe the role of PCL2 in both modulating transcription of ESC self-renewal genes in undifferentiated ESCs as well as developmental regulators during early commitment and differentiation. PMID:20144788

The RNA-editing enzyme ADAR1 controls innate immune responses to RNA.

PubMed

Mannion, Niamh M; Greenwood, Sam M; Young, Robert; Cox, Sarah; Brindle, James; Read, David; Nellåker, Christoffer; Vesely, Cornelia; Ponting, Chris P; McLaughlin, Paul J; Jantsch, Michael F; Dorin, Julia; Adams, Ian R; Scadden, A D J; Ohman, Marie; Keegan, Liam P; O'Connell, Mary A

2014-11-20

The ADAR RNA-editing enzymes deaminate adenosine bases to inosines in cellular RNAs. Aberrant interferon expression occurs in patients in whom ADAR1 mutations cause Aicardi-Goutières syndrome (AGS) or dystonia arising from striatal neurodegeneration. Adar1 mutant mouse embryos show aberrant interferon induction and die by embryonic day E12.5. We demonstrate that Adar1 embryonic lethality is rescued to live birth in Adar1; Mavs double mutants in which the antiviral interferon induction response to cytoplasmic double-stranded RNA (dsRNA) is prevented. Aberrant immune responses in Adar1 mutant mouse embryo fibroblasts are dramatically reduced by restoring the expression of editing-active cytoplasmic ADARs. We propose that inosine in cellular RNA inhibits antiviral inflammatory and interferon responses by altering RLR interactions. Transfecting dsRNA oligonucleotides containing inosine-uracil base pairs into Adar1 mutant mouse embryo fibroblasts reduces the aberrant innate immune response. ADAR1 mutations causing AGS affect the activity of the interferon-inducible cytoplasmic isoform more severely than the nuclear isoform. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Adult Human Gingival Epithelial Cells as a Source for Whole-tooth Bioengineering

PubMed Central

Angelova Volponi, A.; Kawasaki, M.; Sharpe, P.T.

2013-01-01

Teeth develop from interactions between embryonic oral epithelium and neural-crest-derived mesenchyme. These cells can be separated into single-cell populations and recombined to form normal teeth, providing a basis for bioengineering new teeth if suitable, non-embryonic cell sources can be identified. We show here that cells can be isolated from adult human gingival tissue that can be expanded in vitro and, when combined with mouse embryonic tooth mesenchyme cells, form teeth. Teeth with developing roots can be produced from this cell combination following transplantation into renal capsules. These bioengineered teeth contain dentin and enamel with ameloblast-like cells and rests of Malassez of human origin. PMID:23458883

Human embryonic stem cell-derived pancreatic endoderm alleviates diabetic pathology and improves reproductive outcome in C57BL/KsJ-Lep(db/+) gestational diabetes mellitus mice.

PubMed

Xing, Baoheng; Wang, Lili; Li, Qin; Cao, Yalei; Dong, Xiujuan; Liang, Jun; Wu, Xiaohua

2015-07-01

Gestational diabetes mellitus is a condition commonly encountered during mid to late pregnancy with pathologic manifestations including hyperglycemia, hyperinsulinemia, insulin resistance, and fetal maldevelopment. The cause of gestational diabetes mellitus can be attributed to both genetic and environmental factors, hence complicating its diagnosis and treatment. Pancreatic progenitors derived from human embryonic stem cells were shown to be able to effectively treat diabetes in mice. In this study, we have developed a system of treating diabetes using human embryonic stem cell-derived pancreatic endoderm in a mouse model of gestational diabetes mellitus. Human embryonic stem cells were differentiated in vitro into pancreatic endoderm, which were then transplanted into db/+ mice suffering from gestational diabetes mellitus. The transplant greatly improved glucose metabolism and reproductive outcome of the females compared with the control groups. Our findings support the feasibility of using differentiated human embryonic stem cells for treating gestational diabetes mellitus patients. Copyright © 2015 Elsevier Inc. All rights reserved.

Use of micro computed-tomography and 3D printing for reverse engineering of mouse embryo nasal capsule

NASA Astrophysics Data System (ADS)

Tesařová, M.; Zikmund, T.; Kaucká, M.; Adameyko, I.; Jaroš, J.; Paloušek, D.; Škaroupka, D.; Kaiser, J.

2016-03-01

Imaging of increasingly complex cartilage in vertebrate embryos is one of the key tasks of developmental biology. This is especially important to study shape-organizing processes during initial skeletal formation and growth. Advanced imaging techniques that are reflecting biological needs give a powerful impulse to push the boundaries of biological visualization. Recently, techniques for contrasting tissues and organs have improved considerably, extending traditional 2D imaging approaches to 3D . X-ray micro computed tomography (μCT), which allows 3D imaging of biological objects including their internal structures with a resolution in the micrometer range, in combination with contrasting techniques seems to be the most suitable approach for non-destructive imaging of embryonic developing cartilage. Despite there are many software-based ways for visualization of 3D data sets, having a real solid model of the studied object might give novel opportunities to fully understand the shape-organizing processes in the developing body. In this feasibility study we demonstrated the full procedure of creating a real 3D object of mouse embryo nasal capsule, i.e. the staining, the μCT scanning combined by the advanced data processing and the 3D printing.

An efficient method for generation of bi-allelic null mutant mouse embryonic stem cells and its application for investigating epigenetic modifiers

PubMed Central

Cho, Lily Ting-yin; Andrews, Robert; Carroll, Thomas; Iyer, Vivek; Tate, Peri; Rosen, Barry; Stunnenberg, Hendrik G.; Fisher, Amanda G.; Skarnes, William C.

2017-01-01

Abstract Mouse embryonic stem (ES) cells are a popular model system to study biological processes, though uncovering recessive phenotypes requires inactivating both alleles. Building upon resources from the International Knockout Mouse Consortium (IKMC), we developed a targeting vector for second allele inactivation in conditional-ready IKMC ‘knockout-first’ ES cell lines. We applied our technology to several epigenetic regulators, recovering bi-allelic targeted clones with a high efficiency of 60% and used Flp recombinase to restore expression in two null cell lines to demonstrate how our system confirms causality through mutant phenotype reversion. We designed our strategy to select against re-targeting the ‘knockout-first’ allele and identify essential genes in ES cells, including the histone methyltransferase Setdb1. For confirmation, we exploited the flexibility of our system, enabling tamoxifen inducible conditional gene ablation while controlling for genetic background and tamoxifen effects. Setdb1 ablated ES cells exhibit severe growth inhibition, which is not rescued by exogenous Nanog expression or culturing in naive pluripotency ‘2i’ media, suggesting that the self-renewal defect is mediated through pluripotency network independent pathways. Our strategy to generate null mutant mouse ES cells is applicable to thousands of genes and repurposes existing IKMC Intermediate Vectors. PMID:28981838

Reprogramming fibroblasts into induced pluripotent stem cells with Bmi1

PubMed Central

Moon, Jai-Hee; Heo, June Seok; Kim, Jun Sung; Jun, Eun Kyoung; Lee, Jung Han; Kim, Aeree; Kim, Jonggun; Whang, Kwang Youn; Kang, Yong-Kook; Yeo, Seungeun; Lim, Hee-Joung; Han, Dong Wook; Kim, Dong-Wook; Oh, Sejong; Yoon, Byung Sun; Schöler, Hans R; You, Seungkwon

2011-01-01

Somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by the transcription factors Oct4, Sox2, and Klf4 in combination with c-Myc. Recently, Sox2 plus Oct4 was shown to reprogram fibroblasts and Oct4 alone was able to reprogram mouse and human neural stem cells (NSCs) into iPS cells. Here, we report that Bmi1 leads to the transdifferentiation of mouse fibroblasts into NSC-like cells, and, in combination with Oct4, can replace Sox2, Klf4 and c-Myc during the reprogramming of fibroblasts into iPS cells. Furthermore, activation of sonic hedgehog signaling (by Shh, purmorphamine, or oxysterol) compensates for the effects of Bmi1, and, in combination with Oct4, reprograms mouse embryonic and adult fibroblasts into iPS cells. One- and two-factor iPS cells are similar to mouse embryonic stem cells in their global gene expression profile, epigenetic status, and in vitro and in vivo differentiation into all three germ layers, as well as teratoma formation and germline transmission in vivo. These data support that converting fibroblasts with Bmi1 or activation of the sonic hedgehog pathway to an intermediate cell type that expresses Sox2, Klf4, and N-Myc allows iPS generation via the addition of Oct4. PMID:21709693

Mouse hypospadias: A critical examination and definition

PubMed Central

Sinclair, Adriane Watkins; Cao, Mei; Shen, Joel; Cooke, Paul; Risbridger, Gail; Baskin, Laurence; Cunha, Gerald R.

2016-01-01

Hypospadias is a common malformation whose etiology is based upon perturbation of normal penile development. The mouse has been previously used as a model of hypospadias, despite an unacceptably wide range of definitions for this malformation. The current paper presents objective criteria and a definition of mouse hypospadias. Accordingly, diethylstilbestrol (DES) induced penile malformations were examined at 60 days postnatal (P60) in mice treated with DES over the age range of 12 days embryonic to 20 days postnatal (E12 to P20). DES-induced hypospadias involves malformation of the urethral meatus, which is most severe in DES E12-P10, DES P0-P10 and DES P5-P15 groups and less so or absent in the other treatment groups. A frenulum-like ventral tether between the penis and the prepuce was seen in the most severely affected DES-treated mice. Internal penile morphology was also altered in the DES E12-P10, DES P0-P10 and DES P5-P15 groups (with little effect in the other DES treatment groups). Thus, adverse effects of DES are a function of the period of DES treatment and most severe in the P0 to P10 period. In “estrogen mutant mice” (NERKI, βERKO, αERKO and AROM+) hypospadias was only seen in AROM+ male mice having genetically-engineered elevation is serum estrogen. Significantly, mouse hypospadias was only seen distally at and near the urethral meatus where epithelial fusion events are known to take place and never in the penile midshaft, where urethral formation occurs via an entirely different morphogenetic process. PMID:27068029

Lack of Phenotypical and Morphological Evidences of Endothelial to Hematopoietic Transition in the Murine Embryonic Head during Hematopoietic Stem Cell Emergence.

PubMed

Iizuka, Kazuhide; Yokomizo, Tomomasa; Watanabe, Naoki; Tanaka, Yosuke; Osato, Motomi; Takaku, Tomoiku; Komatsu, Norio

2016-01-01

During mouse ontogeny, hematopoietic cells arise from specialized endothelial cells, i.e., the hemogenic endothelium, and form clusters in the lumen of arterial vessels. Hemogenic endothelial cells have been observed in several embryonic tissues, such as the dorsal aorta, the placenta and the yolk sac. Recent work suggests that the mouse embryonic head also produces hematopoietic stem cells (HSCs)/progenitors. However, a histological basis for HSC generation in the head has not yet been determined because the hematopoietic clusters and hemogenic endothelium in the head region have not been well characterized. In this study, we used whole-mount immunostaining and 3D confocal reconstruction techniques to analyze both c-Kit+ hematopoietic clusters and Runx1+ hemogenic endothelium in the whole-head vasculature. The number of c-Kit+ hematopoietic cells was 20-fold less in the head arteries than in the dorsal aorta. In addition, apparent nascent hematopoietic cells, which are characterized by a "budding" structure and a Runx1+ hemogenic endothelium, were not observed in the head. These results suggest that head HSCs may not be or are rarely generated from the endothelium in the same manner as aortic HSCs.

Lack of Phenotypical and Morphological Evidences of Endothelial to Hematopoietic Transition in the Murine Embryonic Head during Hematopoietic Stem Cell Emergence

PubMed Central

Iizuka, Kazuhide; Yokomizo, Tomomasa; Watanabe, Naoki; Tanaka, Yosuke; Osato, Motomi; Takaku, Tomoiku; Komatsu, Norio

2016-01-01

During mouse ontogeny, hematopoietic cells arise from specialized endothelial cells, i.e., the hemogenic endothelium, and form clusters in the lumen of arterial vessels. Hemogenic endothelial cells have been observed in several embryonic tissues, such as the dorsal aorta, the placenta and the yolk sac. Recent work suggests that the mouse embryonic head also produces hematopoietic stem cells (HSCs)/progenitors. However, a histological basis for HSC generation in the head has not yet been determined because the hematopoietic clusters and hemogenic endothelium in the head region have not been well characterized. In this study, we used whole-mount immunostaining and 3D confocal reconstruction techniques to analyze both c-Kit+ hematopoietic clusters and Runx1+ hemogenic endothelium in the whole-head vasculature. The number of c-Kit+ hematopoietic cells was 20-fold less in the head arteries than in the dorsal aorta. In addition, apparent nascent hematopoietic cells, which are characterized by a “budding” structure and a Runx1+ hemogenic endothelium, were not observed in the head. These results suggest that head HSCs may not be or are rarely generated from the endothelium in the same manner as aortic HSCs. PMID:27227884

Generation of eggs from mouse embryonic stem cells and induced pluripotent stem cells.

PubMed

Hayashi, Katsuhiko; Saitou, Mitinori

2013-08-01

Oogenesis is an integrated process through which an egg acquires the potential for totipotency, a fundamental condition for creating new individuals. Reconstitution of oogenesis in a culture that generates eggs with proper function from pluripotent stem cells (PSCs) is therefore one of the key goals in basic biology as well as in reproductive medicine. Here we describe a stepwise protocol for the generation of eggs from mouse PSCs, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). ESCs and iPSCs are first induced into primordial germ cell-like cells (PGCLCs) that are in turn aggregated with somatic cells of female embryonic gonads, the precursors for adult ovaries. Induction of PGCLCs followed by aggregation with the somatic cells takes up to 8 d. The aggregations are then transplanted under the ovarian bursa, in which PGCLCs grow into germinal vesicle (GV) oocytes in ∼1 month. The PGCLC-derived GV oocytes can be matured into eggs in 1 d by in vitro maturation (IVM), and they can be fertilized with spermatozoa by in vitro fertilization (IVF) to obtain healthy and fertile offspring. This method provides an initial step toward reconstitution of the entire process of oogenesis in vitro.

Heterogeneity in Oct4 and Sox2 Targets Biases Cell Fate in 4-Cell Mouse Embryos.

PubMed

Goolam, Mubeen; Scialdone, Antonio; Graham, Sarah J L; Macaulay, Iain C; Jedrusik, Agnieszka; Hupalowska, Anna; Voet, Thierry; Marioni, John C; Zernicka-Goetz, Magdalena

2016-03-24

The major and essential objective of pre-implantation development is to establish embryonic and extra-embryonic cell fates. To address when and how this fundamental process is initiated in mammals, we characterize transcriptomes of all individual cells throughout mouse pre-implantation development. This identifies targets of master pluripotency regulators Oct4 and Sox2 as being highly heterogeneously expressed between blastomeres of the 4-cell embryo, with Sox21 showing one of the most heterogeneous expression profiles. Live-cell tracking demonstrates that cells with decreased Sox21 yield more extra-embryonic than pluripotent progeny. Consistently, decreasing Sox21 results in premature upregulation of the differentiation regulator Cdx2, suggesting that Sox21 helps safeguard pluripotency. Furthermore, Sox21 is elevated following increased expression of the histone H3R26-methylase CARM1 and is lowered following CARM1 inhibition, indicating the importance of epigenetic regulation. Therefore, our results indicate that heterogeneous gene expression, as early as the 4-cell stage, initiates cell-fate decisions by modulating the balance of pluripotency and differentiation. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Copine1 regulates neural stem cell functions during brain development.

PubMed

Kim, Tae Hwan; Sung, Soo-Eun; Cheal Yoo, Jae; Park, Jae-Yong; Yi, Gwan-Su; Heo, Jun Young; Lee, Jae-Ran; Kim, Nam-Soon; Lee, Da Yong

2018-01-01

Copine 1 (CPNE1) is a well-known phospholipid binding protein in plasma membrane of various cell types. In brain cells, CPNE1 is closely associated with AKT signaling pathway, which is important for neural stem cell (NSC) functions during brain development. Here, we investigated the role of CPNE1 in the regulation of brain NSC functions during brain development and determined its underlying mechanism. In this study, abundant expression of CPNE1 was observed in neural lineage cells including NSCs and immature neurons in human. With mouse brain tissues in various developmental stages, we found that CPNE1 expression was higher at early embryonic stages compared to postnatal and adult stages. To model developing brain in vitro, we used primary NSCs derived from mouse embryonic hippocampus. Our in vitro study shows decreased proliferation and multi-lineage differentiation potential in CPNE1 deficient NSCs. Finally, we found that the deficiency of CPNE1 downregulated mTOR signaling in embryonic NSCs. These data demonstrate that CPNE1 plays a key role in the regulation of NSC functions through the activation of AKT-mTOR signaling pathway during brain development. Copyright © 2017 Elsevier Inc. All rights reserved.

Determination of the reactivity of cytotoxic immune cells with preimplantation mouse embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ewoldsen, M.A.

1987-01-01

Cytotoxic immune cells were used in an assay, MELIA (mixed embryo leukocyte interaction assay) to test the ability of the cells to kill blastocyst stage embryos. The cytotoxic immune cells generated for use in this study, cytotoxic T lymphocytes (CTLs), natural killer (NK) cells, and lymphokine activated killer (LAK) cells were shown to have phenotypic and cytolytic characteristics similar to those reported by other investigators. The lysis of the blastocysts in the MELIA was determined by measuring the inhibition of blastocoel retention and/or by the inhibition of incorporation of tritiated thymidine (/sup 3/H-TdR) into embryonic DNA. Blastocysts which possess ormore » lack their zonae pellucidae were tested to determine whether the zona pellucida plays an immunoprotective role in preimplantation development. The results indicated that CTLs only lysed embryonic cells when the zona pellucida was absent, but NK and LAK cells lysed embryonic cells whether the zona pellucida was present or absent. The results suggest that the zona pellucida may protect the preimplantation mouse embryo from lysis by CTLs but what protects the embryo from lysis by NK and LAK cells is unclear.« less

RTEL1 contributes to DNA replication and repair and telomere maintenance.

PubMed

Uringa, Evert-Jan; Lisaingo, Kathleen; Pickett, Hilda A; Brind'Amour, Julie; Rohde, Jan-Hendrik; Zelensky, Alex; Essers, Jeroen; Lansdorp, Peter M

2012-07-01

Telomere maintenance and DNA repair are important processes that protect the genome against instability. mRtel1, an essential helicase, is a dominant factor setting telomere length in mice. In addition, mRtel1 is involved in DNA double-strand break repair. The role of mRtel1 in telomere maintenance and genome stability is poorly understood. Therefore we used mRtel1-deficient mouse embryonic stem cells to examine the function of mRtel1 in replication, DNA repair, recombination, and telomere maintenance. mRtel1-deficient mouse embryonic stem cells showed sensitivity to a range of DNA-damaging agents, highlighting its role in replication and genome maintenance. Deletion of mRtel1 increased the frequency of sister chromatid exchange events and suppressed gene replacement, demonstrating the involvement of the protein in homologous recombination. mRtel1 localized transiently at telomeres and is needed for efficient telomere replication. Of interest, in the absence of mRtel1, telomeres in embryonic stem cells appeared relatively stable in length, suggesting that mRtel1 is required to allow extension by telomerase. We propose that mRtel1 is a key protein for DNA replication, recombination, and repair and efficient elongation of telomeres by telomerase.

CRISPR/Cas9-Mediated Insertion of loxP Sites in the Mouse Dock7 Gene Provides an Effective Alternative to Use of Targeted Embryonic Stem Cells.

PubMed

Bishop, Kathleen A; Harrington, Anne; Kouranova, Evguenia; Weinstein, Edward J; Rosen, Clifford J; Cui, Xiaoxia; Liaw, Lucy

2016-07-07

Targeted gene mutation in the mouse is a primary strategy to understand gene function and relation to phenotype. The Knockout Mouse Project (KOMP) had an initial goal to develop a public resource of mouse embryonic stem (ES) cell clones that carry null mutations in all genes. Indeed, many useful novel mouse models have been generated from publically accessible targeted mouse ES cell lines. However, there are limitations, including incorrect targeting or cassette structure, and difficulties with germline transmission of the allele from chimeric mice. In our experience, using a small sample of targeted ES cell clones, we were successful ∼50% of the time in generating germline transmission of a correctly targeted allele. With the advent of CRISPR/Cas9 as a mouse genome modification tool, we assessed the efficiency of creating a conditional targeted allele in one gene, dedicator of cytokinesis 7 (Dock7), for which we were unsuccessful in generating a null allele using a KOMP targeted ES cell clone. The strategy was to insert loxP sites to flank either exons 3 and 4, or exons 3 through 7. By coinjecting Cas9 mRNA, validated sgRNAs, and oligonucleotide donors into fertilized eggs from C57BL/6J mice, we obtained a variety of alleles, including mice homozygous for the null alleles mediated by nonhomologous end joining, alleles with one of the two desired loxP sites, and correctly targeted alleles with both loxP sites. We also found frequent mutations in the inserted loxP sequence, which is partly attributable to the heterogeneity in the original oligonucleotide preparation. Copyright © 2016 Bishop et al.

Angiotensin II increases Pax-2 expression in fetal kidney cells via the AT2 receptor.

PubMed

Zhang, Shao-Ling; Moini, Babak; Ingelfinger, Julie R

2004-06-01

Although both the renin angiotensin system (RAS) and the paired homeobox 2 gene (Pax-2) seem critically important in renal organogenesis, whether and how they might interact has not been addressed. The present study asked whether a link between the RAS and Pax-2 exists in fetal renal cells, speculating that such an interaction, if present, might influence renal development. Embryonic kidney explants and embryonic renal cells (mouse late embryonic mesenchymal epithelial cells [MK4] and mouse early embryonic mesenchymal fibroblasts [MK3]) were used. Pax-2 protein and Pax-2 mRNA were detected by immunofluorescence, Western blot, reverse transcription-PCR, and real-time PCR. Angiotensin II (AngII) upregulated Pax-2 protein and Pax-2 mRNA expression via the AngII type 2 (AT(2)) receptor in MK4 but not in MK3 cells. The stimulatory effect of AngII on Pax-2 gene expression could be blocked by PD123319 (AT(2) inhibitor), AG 490 (a specific Janus kinase 2 inhibitor), and genistein (a tyrosine kinase inhibitor) but not by losartan (AT(1) inhibitor), SB203580 (specific p38 mitogen-activated protein kinase inhibitor), PD98059 (specific MEK inhibitor), SP600125 (JNK inhibitor), and diphenyleneiodonium chloride (an NADPH oxidase inhibitor). Moreover, embryonic kidney explants in culture confirmed that AngII upregulates Pax-2 gene expression via the AT(2) receptor. These studies demonstrate that the stimulatory effect of AngII on Pax-2 gene expression is mediated, at least in part, via the Janus kinase 2/signal transducers and activators of transcription signaling transduction pathway, suggesting that RAS and Pax-2 interactions may be important in renal development.

The effects of triclosan on pluripotency factors and development of mouse embryonic stem cells and zebrafish.

PubMed

Chen, Xiaojiao; Xu, Bo; Han, Xiumei; Mao, Zhilei; Chen, Minjian; Du, Guizhen; Talbot, Prue; Wang, Xinru; Xia, Yankai

2015-04-01

Triclosan (TCS) poses potential risks to reproduction and development due to its endocrine-disrupting properties. However, the mechanism of TCS's effects on early embryonic development is little known. Embryonic stem cells (ESC) and zebrafish embryos provide valuable models for testing the toxic effects of environmental chemicals on early embryogenesis. In this study, mouse embryonic stem cells (mESC) were acutely exposed to TCS for 24 h, and general cytotoxicity and the effect of TCS on pluripotency were then evaluated. In addition, zebrafish embryos were exposed to TCS from 2- to 24-h post-fertilization (hpf), and their morphology was evaluated. In mESC, alkaline phosphatase staining was significantly decreased after treatment with the highest concentration of TCS (50 μM). Although the expression levels of Sox2 mRNA were not changed, the mRNA levels of Oct4 and Nanog in TCS-treated groups were significantly decreased compared to controls. In addition, the protein levels of Oct4, Sox2 and Nanog were significantly reduced in response to TCS treatment. MicroRNA (miR)-134, an expression inhibitor of pluripotency markers, was significantly increased in TCS-treated mESC. In zebrafish experiments, after 24 hpf of treatment, the controls had developed to the late stage of somitogenesis, while embryos exposed to 300 μg/L of TCS were still at the early stage of somitogenesis, and three genes (Oct4, Sox2 and Nanog) were upregulated in treated groups when compared with the controls. The two models demonstrated that TCS may affect early embryonic development by disturbing the expression of the pluripotency markers (Oct4, Sox2 and Nanog).

FACS-based isolation, propagation and characterization of mouse embryonic cardiomyocytes based on VCAM-1 surface marker expression.

PubMed

Pontén, Annica; Walsh, Stuart; Malan, Daniela; Xian, Xiaojie; Schéele, Susanne; Tarnawski, Laura; Fleischmann, Bernd K; Jovinge, Stefan

2013-01-01

Purification of cardiomyocytes from the embryonic mouse heart, embryonic stem (ES) or induced pluripotent stem cells (iPS) is a challenging task and will require specific isolation procedures. Lately the significance of surface markers for the isolation of cardiac cell populations with fluorescence activated cell sorting (FACS) has been acknowledged, and the hunt for cardiac specific markers has intensified. As cardiomyocytes have traditionally been characterized by their expression of specific transcription factors and structural proteins, and not by specific surface markers, this constitutes a significant bottleneck. Lately, Flk-1, c-kit and the cellular prion protein have been reported to specify cardiac progenitors, however, no surface markers have so far been reported to specify a committed cardiomyocyte. Herein show for the first time, that embryonic cardiomyocytes can be isolated with 98% purity, based on their expression of vascular cell adhesion molecule-1 (VCAM-1). The FACS-isolated cells express phenotypic markers for embryonic committed cardiomyocytes but not cardiac progenitors. An important aspect of FACS is to provide viable cells with retention of functionality. We show that VCAM-1 positive cardiomyocytes can be isolated with 95% viability suitable for in vitro culture, functional assays or expression analysis. In patch-clamp experiments we provide evidence of functionally intact cardiomyocytes of both atrial and ventricular subtypes. This work establishes that cardiomyocytes can be isolated with a high degree of purity and viability through FACS, based on specific surface marker expression as has been done in the hematopoietic field for decades. Our FACS protocol represents a significant advance in which purified populations of cardiomyocytes may be isolated and utilized for downstream applications, such as purification of ES-cell derived cardiomyocytes.

FACS-Based Isolation, Propagation and Characterization of Mouse Embryonic Cardiomyocytes Based on VCAM-1 Surface Marker Expression

PubMed Central

Pontén, Annica; Walsh, Stuart; Malan, Daniela; Xian, Xiaojie; Schéele, Susanne; Tarnawski, Laura; Fleischmann, Bernd K.; Jovinge, Stefan

2013-01-01

Purification of cardiomyocytes from the embryonic mouse heart, embryonic stem (ES) or induced pluripotent stem cells (iPS) is a challenging task and will require specific isolation procedures. Lately the significance of surface markers for the isolation of cardiac cell populations with fluorescence activated cell sorting (FACS) has been acknowledged, and the hunt for cardiac specific markers has intensified. As cardiomyocytes have traditionally been characterized by their expression of specific transcription factors and structural proteins, and not by specific surface markers, this constitutes a significant bottleneck. Lately, Flk-1, c-kit and the cellular prion protein have been reported to specify cardiac progenitors, however, no surface markers have so far been reported to specify a committed cardiomyocyte. Herein show for the first time, that embryonic cardiomyocytes can be isolated with 98% purity, based on their expression of vascular cell adhesion molecule-1 (VCAM-1). The FACS-isolated cells express phenotypic markers for embryonic committed cardiomyocytes but not cardiac progenitors. An important aspect of FACS is to provide viable cells with retention of functionality. We show that VCAM-1 positive cardiomyocytes can be isolated with 95% viability suitable for in vitro culture, functional assays or expression analysis. In patch-clamp experiments we provide evidence of functionally intact cardiomyocytes of both atrial and ventricular subtypes. This work establishes that cardiomyocytes can be isolated with a high degree of purity and viability through FACS, based on specific surface marker expression as has been done in the hematopoietic field for decades. Our FACS protocol represents a significant advance in which purified populations of cardiomyocytes may be isolated and utilized for downstream applications, such as purification of ES-cell derived cardiomyocytes. PMID:24386094

EXTRA-EMBRYONIC-SPECIFIC IMPRINTED EXPRESSION IS RESTRICTED TO DEFINED LINEAGES IN THE POST-IMPLANTATION EMBRYO

PubMed Central

Hudson, Quanah J.; Seidl, Christine I.M.; Kulinski, Tomasz M.; Huang, Ru; Warczok, Katarzyna E.; Bittner, Romana; Bartolomei, Marisa S.; Barlow, Denise P.

2011-01-01

A subset of imprinted genes in the mouse have been reported to show imprinted expression that is restricted to the placenta, a short-lived extra-embryonic organ. Notably these so-called 'placental-specific' imprinted genes are expressed from both parental alleles in embryo and adult tissues. The placenta is an embryonic-derived organ that is closely associated with maternal tissue and as a consequence, maternal contamination can be mistaken for maternal-specific imprinted expression. The complexity of the placenta, which arises from multiple embryonic lineages, poses additional problems in accurately assessing allele-specific repressive epigenetic modifications in genes that also show lineage-specific silencing in this organ. These problems require that extra evidence be obtained to support the imprinted status of genes whose imprinted expression is restricted to the placenta. We show here that the extra-embryonic visceral yolk sac (VYS), a nutritive membrane surrounding the developing embryo, shows a similar 'extra-embryonic-lineage-specific' pattern of imprinted expression. We present an improved enzymatic technique for separating the bilaminar VYS and show that this pattern of imprinted expression is restricted to the endoderm layer. Finally, we show that VYS 'extra-embryonic-lineage-specific' imprinted expression is regulated by DNA methylation in a similar manner as shown for genes showing multi-lineage imprinted expression in extra-embryonic, embryonic and adult tissues. These results show that the VYS is an improved model for studying the epigenetic mechanisms regulating extra-embryonic-lineage-specific imprinted expression. PMID:21354127

An Optimized and Simplified System of Mouse Embryonic Stem Cell Cardiac Differentiation for the Assessment of Differentiation Modifiers

PubMed Central

Hartman, Matthew E.; Librande, Jason R.; Medvedev, Ivan O.; Ahmad, Rabiah N.; Moussavi-Harami, Farid; Gupta, Pritha P.; Chien, Wei-Ming; Chin, Michael T.

2014-01-01

Generating cardiomyocytes from embryonic stem cells is an important technique for understanding cardiovascular development, the origins of cardiovascular diseases and also for providing potential reagents for cardiac repair. Numerous methods have been published but often are technically challenging, complex, and are not easily adapted to assessment of specific gene contributions to cardiac myocyte differentiation. Here we report the development of an optimized protocol to induce the differentiation of mouse embryonic stem cells to cardiac myocytes that is simplified and easily adapted for genetic studies. Specifically, we made four critical findings that distinguish our protocol: 1) mouse embryonic stem cells cultured in media containing CHIR99021 and PD0325901 to maintain pluripotency will efficiently form embryoid bodies containing precardiac mesoderm when cultured in these factors at a reduced dosage, 2) low serum conditions promote cardiomyocyte differentiation and can be used in place of commercially prepared StemPro nutrient supplement, 3) the Wnt inhibitor Dkk-1 is dispensable for efficient cardiac differentiation and 4) tracking differentiation efficiency may be done with surface expression of PDGFRα alone. In addition, cardiac mesodermal precursors generated by this system can undergo lentiviral infection to manipulate the expression of specific target molecules to assess effects on cardiac myocyte differentiation and maturation. Using this approach, we assessed the effects of CHF1/Hey2 on cardiac myocyte differentiation, using both gain and loss of function. Overexpression of CHF1/Hey2 at the cardiac mesoderm stage had no apparent effect on cardiac differentiation, while knockdown of CHF1/Hey2 resulted in increased expression of atrial natriuretic factor and connexin 43, suggesting an alteration in the phenotype of the cardiomyocytes. In summary we have generated a detailed and simplified protocol for generating cardiomyocytes from mES cells that is optimized for investigating factors that affect cardiac differentiation. PMID:24667642

Developmental expression of membrane type 4-matrix metalloproteinase (Mt4-mmp/Mmp17) in the mouse embryo

PubMed Central

Clemente, Cristina; Montalvo, María Gregoria; Seiki, Motoharu; Arroyo, Alicia G.

2017-01-01

Matrix metalloproteinases (MMPs) constitute a large group of endoproteases that play important functions during embryonic development, tumor metastasis and angiogenesis by degrading components of the extracellular matrix. Within this family, we focused our study on Mt4-mmp (also called Mmp17) that belongs to a distinct subset that is anchored to the cell surface via a glycosylphosphatidylinositol (GPI) moiety and with the catalytic site exposed to the extracellular space. Information about its function and substrates is very limited to date, and little has been reported on its role in the developing embryo. Here, we report a detailed expression analysis of Mt4-mmp during mouse embryonic development by using a LacZ reporter transgenic mouse line. We showed that Mt4-mmp is detected from early stages of development to postnatal stages following a dynamic and restricted pattern of expression. Mt4-mmp was first detected at E8.5 limited to the intersomitic vascularization, the endocardial endothelium and the dorsal aorta. Mt4-mmpLacZ/+ cells were also observed in the neural crest cells, somites, floor plate and notochord at early stages. From E10.5, expression localized in the limb buds and persists during limb development. A strong expression in the brain begins at E12.5 and continues to postnatal stages. Specifically, staining was observed in the olfactory bulb, cerebral cortex, hippocampus, striatum, septum, dorsal thalamus and the spinal cord. In addition, LacZ-positive cells were also detected during eye development, initially at the hyaloid artery and later on located in the lens and the neural retina. Mt4-mmp expression was confirmed by quantitative RT-PCR and western blot analysis in some embryonic tissues. Our data point to distinct functions for this metalloproteinase during embryonic development, particularly during brain formation, angiogenesis and limb development. PMID:28926609

The role of nanotechnology in induced pluripotent and embryonic stem cells research.

PubMed

Chen, Lukui; Qiu, Rong; Li, Lushen

2014-12-01

This paper reviews the recent studies on development of nanotechnology in the field of induced pluripotent and embryonic stem cells. Stem cell therapy is a promising therapy that can improve the quality of life for patients with refractory diseases. However, this option is limited by the scarcity of tissues, ethical problem, and tumorigenicity. Nanotechnology is another promising therapy that can be used to mimic the extracellular matrix, label the implanted cells, and also can be applied in the tissue engineering. In this review, we briefly introduce implementation of nanotechnology in induced pluripotent and embryonic stem cells research. Finally, the potential application of nanotechnology in tissue engineering and regenerative medicine is also discussed.

Assembly of embryonic and extraembryonic stem cells to mimic embryogenesis in vitro.

PubMed

Harrison, Sarah Ellys; Sozen, Berna; Christodoulou, Neophytos; Kyprianou, Christos; Zernicka-Goetz, Magdalena

2017-04-14

Mammalian embryogenesis requires intricate interactions between embryonic and extraembryonic tissues to orchestrate and coordinate morphogenesis with changes in developmental potential. Here, we combined mouse embryonic stem cells (ESCs) and extraembryonic trophoblast stem cells (TSCs) in a three-dimensional scaffold to generate structures whose morphogenesis is markedly similar to that of natural embryos. By using genetically modified stem cells and specific inhibitors, we show that embryogenesis of ESC- and TSC-derived embryos-ETS-embryos-depends on cross-talk involving Nodal signaling. When ETS-embryos develop, they spontaneously initiate expression of mesoderm and primordial germ cell markers asymmetrically on the embryonic and extraembryonic border, in response to Wnt and BMP signaling. Our study demonstrates the ability of distinct stem cell types to self-assemble in vitro to generate embryos whose morphogenesis, architecture, and constituent cell types resemble those of natural embryos. Copyright © 2017, American Association for the Advancement of Science.

Embryonic stem cells improve skeletal muscle recovery after extreme atrophy in mice.

PubMed

Artioli, Guilherme Giannini; De Oliveira Silvestre, João Guilherme; Guilherme, João Paulo Limongi França; Baptista, Igor Luchini; Ramos, Gracielle Vieira; Da Silva, Willian José; Miyabara, Elen Haruka; Moriscot, Anselmo Sigari

2015-03-01

We injected embryonic stem cells into mouse tibialis anterior muscles subjected to botulinum toxin injections as a model for reversible neurogenic atrophy. Muscles were exposed to botulinum toxin for 4 weeks and allowed to recover for up to 6 weeks. At the onset of recovery, a single muscle injection of embryonic stem cells was administered. The myofiber cross-sectional area, single twitch force, peak tetanic force, time-to-peak force, and half-relaxation time were determined. Although the stem cell injection did not affect the myofiber cross-sectional area gain in recovering muscles, most functional parameters improved significantly compared with those of recovering muscles that did not receive the stem cell injection. Muscle function recovery was accelerated by embryonic stem cell delivery in this durable neurogenic atrophy model. We conclude that stem cells should be considered a potential therapeutic tool for recovery after extreme skeletal muscle atrophy. © 2014 Wiley Periodicals, Inc.

A structure-based extracellular matrix expansion mechanism of fibrous tissue growth.

PubMed

Kalson, Nicholas S; Lu, Yinhui; Taylor, Susan H; Starborg, Tobias; Holmes, David F; Kadler, Karl E

2015-05-20

Embryonic growth occurs predominately by an increase in cell number; little is known about growth mechanisms later in development when fibrous tissues account for the bulk of adult vertebrate mass. We present a model for fibrous tissue growth based on 3D-electron microscopy of mouse tendon. We show that the number of collagen fibrils increases during embryonic development and then remains constant during postnatal growth. Embryonic growth was explained predominately by increases in fibril number and length. Postnatal growth arose predominately from increases in fibril length and diameter. A helical crimp structure was established in embryogenesis, and persisted postnatally. The data support a model where the shape and size of tendon is determined by the number and position of embryonic fibroblasts. The collagen fibrils that these cells synthesise provide a template for postnatal growth by structure-based matrix expansion. The model has important implications for growth of other fibrous tissues and fibrosis.

Regulation of the mouse Treacher Collins syndrome homolog (Tcof1) promoter through differential repression of constitutive expression.

PubMed

Shows, Kathryn H; Shiang, Rita

2008-11-01

Treacher Collins syndrome is an autosomal-dominant mandibulofacial dysostosis caused by haploinsufficiency of the TCOF1 gene product treacle. Mouse Tcof1 protein is approximately 61% identical and 71% similar to treacle, and heterozygous knockout of Tcof1 causes craniofacial malformation. Tcof1 expression is high in developing neural crest, but much lower in other tissues. To investigate this dual regulation, highly conserved regions upstream of TCOF1 homologs were tested through deletion and mutation reporter assays, and conserved predicted transcription factor binding sites were assessed through chromatin binding studies. Assays were performed in mouse P19 embryonic carcinoma cells and in HEK293 cells to determine differential activation in cell types at different stages of differentiation. Binding of Cebpb, Zfp161, and Sp1 transcription factors was specific to the Tcof1 regulatory region in P19 cells. The Zfp161 binding site demonstrated P19 cell-specific repression, while the Sp1/Sp3 candidate site demonstrated HEK293 cell-specific activation. Moreover, presence of c-myb and Zfp161 transcripts was specific to P19 cells. A minimal promoter fragment from -253 to +43 bp directs constitutive expression in both cell types, and dual regulation of Tcof1 appears to be through differential repression of this minimal promoter. The CpG island at the transcription start site remains unmethylated in P19 cells, 11.5 dpc mouse embryonic tissue, and adult mouse ear, which supports constitutive activation of the Tcof1 promoter.

Transcription of mouse Sp2 yields alternatively spliced and sub-genomic mRNAs in a tissue- and cell-type-specific fashion.

PubMed

Yin, Haifeng; Nichols, Teresa D; Horowitz, Jonathan M

2010-07-01

The Sp-family of transcription factors is comprised by nine members, Sp1-9, that share a highly conserved DNA-binding domain. Sp2 is a poorly characterized member of this transcription factor family that is widely expressed in murine and human cell lines yet exhibits little DNA-binding or trans-activation activity in these settings. As a prelude to the generation of a "knock-out" mouse strain, we isolated a mouse Sp2 cDNA and performed a detailed analysis of Sp2 transcription in embryonic and adult mouse tissues. We report that (1) the 5' untranslated region of Sp2 is subject to alternative splicing, (2) Sp2 transcription is regulated by at least two promoters that differ in their cell-type specificity, (3) one Sp2 promoter is highly active in nine mammalian cell lines and strains and is regulated by at least five discrete stimulatory and inhibitory elements, (4) a variety of sub-genomic messages are synthesized from the Sp2 locus in a tissue- and cell-type-specific fashion and these transcripts have the capacity to encode a novel partial-Sp2 protein, and (5) RNA in situ hybridization assays indicate that Sp2 is widely expressed during mouse embryogenesis, particularly in the embryonic brain, and robust Sp2 expression occurs in neurogenic regions of the post-natal and adult brain. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Contrast imaging in mouse embryos using high-frequency ultrasound.

PubMed

Denbeigh, Janet M; Nixon, Brian A; Puri, Mira C; Foster, F Stuart

2015-03-04

Ultrasound contrast-enhanced imaging can convey essential quantitative information regarding tissue vascularity and perfusion and, in targeted applications, facilitate the detection and measure of vascular biomarkers at the molecular level. Within the mouse embryo, this noninvasive technique may be used to uncover basic mechanisms underlying vascular development in the early mouse circulatory system and in genetic models of cardiovascular disease. The mouse embryo also presents as an excellent model for studying the adhesion of microbubbles to angiogenic targets (including vascular endothelial growth factor receptor 2 (VEGFR2) or αvβ3) and for assessing the quantitative nature of molecular ultrasound. We therefore developed a method to introduce ultrasound contrast agents into the vasculature of living, isolated embryos. This allows freedom in terms of injection control and positioning, reproducibility of the imaging plane without obstruction and motion, and simplified image analysis and quantification. Late gestational stage (embryonic day (E)16.6 and E17.5) murine embryos were isolated from the uterus, gently exteriorized from the yolk sac and microbubble contrast agents were injected into veins accessible on the chorionic surface of the placental disc. Nonlinear contrast ultrasound imaging was then employed to collect a number of basic perfusion parameters (peak enhancement, wash-in rate and time to peak) and quantify targeted microbubble binding in an endoglin mouse model. We show the successful circulation of microbubbles within living embryos and the utility of this approach in characterizing embryonic vasculature and microbubble behavior.

Hydrocortisone-induced embryotoxicity and embryonic drug disposition in H-2 congenic mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, L.S.G.

Congenic mouse strains C57BL/10Sn (B10) and B10.A/SgSn(B10A), genetically different only at the H-2 complex, were compared for sensitivity to glucocorticoid-induced embryotoxicity and embryonic drug disposition. B10A mice dosed intramuscularly with 0, 100, 150 and 200 mg hydrocortisone/kg body weight on gestational day twelve, and B10 mice injected with 0, 200, 400, 600, and 800 mg/kg, were evaluated at dissection on gestational day eighteen for signs of toxicity. In both strains, probit analysis of cleft palate production demonstrated a linear dose response. The ED50 for cleft palate production demonstrates a linear dose response. The ED50 for cleft palate production in B10Amore » mice was 143.6 mg/kg and 512.0 mg/kg for the B10 strain. Embryonic exposure was evaluated by administration of /sup 3/H-hydrocortisone (5 uCi/mouse) to pregnant mice on day twelve of gestation, at the ED50 for cleft palate production in B10A strain. The purposes of the experiment were to quantify the difference in susceptibility to steroid-induced cleft palate, determine if a milder manifestation of embryotoxicity, fetal growth retardation, occurred at sub-clefting dosages, and determine if the difference in sensitivity to hydrocortisone-induced embryotoxicity was the result of an underlying difference in embryonic exposure to the teratogen.« less

Maternal topoisomerase II alpha, not topoisomerase II beta, enables embryonic development of zebrafish top2a-/- mutants

PubMed Central

2011-01-01

Background Genetic alterations in human topoisomerase II alpha (TOP2A) are linked to cancer susceptibility. TOP2A decatenates chromosomes and thus is necessary for multiple aspects of cell division including DNA replication, chromosome condensation and segregation. Topoisomerase II alpha is also required for embryonic development in mammals, as mouse Top2a knockouts result in embryonic lethality as early as the 4-8 cell stage. The purpose of this study was to determine whether the extended developmental capability of zebrafish top2a mutants arises from maternal expression of top2a or compensation from its top2b paralogue. Results Here, we describe bloody minded (blm), a novel mutant of zebrafish top2a. In contrast to mouse Top2a nulls, zebrafish top2a mutants survive to larval stages (4-5 day post fertilization). Developmental analyses demonstrate abundant expression of maternal top2a but not top2b. Inhibition or poisoning of maternal topoisomerase II delays embryonic development by extending the cell cycle M-phase. Zygotic top2a and top2b are co-expressed in the zebrafish CNS, but endogenous or ectopic top2b RNA appear unable to prevent the blm phenotype. Conclusions We conclude that maternal top2a enables zebrafish development before the mid-zygotic transition (MZT) and that zebrafish top2a and top2b are not functionally redundant during development after activation of the zygotic genome. PMID:22111588

Developmental bias in cleavage-stage mouse blastomeres

PubMed Central

Tabansky, Inna; Lenarcic, Alan; Draft, Ryan W.; Loulier, Karine; Keskin, Derin B; Rosains, Jacqueline; Rivera-Feliciano, José; Lichtman, Jeff W.; Livet, Jean; Stern, Joel NH; Sanes, Joshua R.; Eggan, Kevin

2012-01-01

Summary Introduction The cleavage stage mouse embryo is composed of superficially equivalent blastomeres that will generate both the embryonic inner cell mass (ICM) and the supportive trophectoderm (TE). However, it remains unsettled whether the contribution of each blastomere to these two lineages can be accounted for by chance. Addressing the question of blastomere cell fate may be of practical importance, as preimplantation genetic diagnosis (PGD) requires removal of blastomeres from the early human embryo. To determine if blastomere allocation to the two earliest lineages is random, we developed and utilized a recombination-mediated, non-invasive combinatorial fluorescent labeling method for embryonic lineage tracing. Results When we induced recombination at cleavage stages, we observed a statistically significant bias in the contribution of the resulting labeled clones to the trophectoderm or the inner cell mass in a subset of embryos. Surprisingly, we did not find a correlation between localization of clones in the embryonic and abembryonic hemispheres of the late blastocyst and their allocation to the TE and ICM, suggesting that TE-ICM bias arises separately from embryonic-abembryonic bias. Rainbow lineage tracing also allowed us to demonstrate that the bias observed in the blastocyst persists into post-implantation stages, and therefore has relevance for subsequent development. Discussion The Rainbow transgenic mice that we describe here have allowed us to detect lineage-dependent bias in early development. They should also enable assessment of the developmental equivalence of mammalian progenitor cells in a variety of tissues. PMID:23177476

Alterations in biosynthetic accumulation of collagen types I and III during growth and morphogenesis of embryonic mouse salivary glands

NASA Technical Reports Server (NTRS)

Hardman, P.; Spooner, B. S.

1992-01-01

We examined the biosynthetic patterns of interstitial collagens in mouse embryonic submandibular and sublingual glands cultured in vitro. Rudiments explanted on day 13 of gestation and cultured for 24, 48, and 72 h all synthesized collagen types I, III, and V. However, while the total incorporation of label into collagenous proteins did not change over the three-day culture period, the rate of accumulation of newly synthesized types I and III did change. At 24 h, the ratio of newly synthesized collagen types I:III was approximately 2, whereas at 72 h, the ratio was approximately 5. These data suggest that collagen types I and III may be important in initiation of branching in this organ, but that type I may become dominant in the later stages of development and in maintenance of the adult organ.

Generating gene knockout rats by homologous recombination in embryonic stem cells

PubMed Central

Tong, Chang; Huang, Guanyi; Ashton, Charles; Li, Ping; Ying, Qi-Long

2013-01-01

We describe here a detailed protocol for generating gene knockout rats by homologous recombination in embryonic stem (ES) cells. This protocol comprises the following procedures: derivation and expansion of rat ES cells, construction of gene-targeting vectors, generation of gene-targeted rat ES cells and, finally, production of gene-targeted rats. The major differences between this protocol and the classical mouse gene-targeting protocol include ES cell culture methods, drug selection scheme, colony picking and screening strategies. This ES cell–based gene-targeting technique allows sophisticated genetic modifications to be performed in the rat, as many laboratories have been doing in the mouse for the past two decades. Recently we used this protocol to generate Tp53 (also known as p53) gene knockout rats. The entire process requires ~1 year to complete, from derivation of ES cells to generation of knockout rats. PMID:21637202

Zscan4 restores the developmental potency of embryonic stem cells

PubMed Central

Amano, Tomokazu; Hirata, Tetsuya; Falco, Geppino; Monti, Manuela; Sharova, Lioudmila V.; Amano, Misa; Sheer, Sarah; Hoang, Hien G.; Piao, Yulan; Stagg, Carole A.; Yamamizu, Kohei; Akiyama, Tomohiko; Ko, Minoru S.H.

2013-01-01

The developmental potency of mouse embryonic stem (ES) cells, which is the ability to contribute to a whole embryo is known to deteriorate during long-term cell culture. Previously we have shown that ES cells oscillate between Zscan4- and Zscan4+ states, and the transient activation of Zscan4 is required for the maintenance of telomeres and genome stability of ES cells. Here we show that increasing the frequency of Zscan4 activation in mouse ES cells restores and maintains their developmental potency in long-term cell culture. Injection of a single ES cell with such increased potency into a tetraploid blastocyst gives rise to an entire embryo with a higher success rate. These results not only provide a means to rejuvenate ES cells by manipulating Zscan4 expression, but also indicate the active roles of Zscan4 in the long-term maintenance of ES cell potency. PMID:23739662

Isolation and characterization of node/notochord-like cells from mouse embryonic stem cells.

PubMed

Winzi, Maria K; Hyttel, Poul; Dale, Jacqueline Kim; Serup, Palle

2011-11-01

The homeobox gene Noto is expressed in the node and its derivative the notochord. Here we use a targeted Noto-GFP reporter to isolate and characterize node/notochord-like cells derived from mouse embryonic stem cells. We find very few Noto-expressing cells after spontaneous differentiation. However, the number of Noto-expressing cells was increased when using Activin A to induce a Foxa2- and Brachyury-expressing progenitor population, whose further differentiation into Noto-expressing cells was improved by simultaneous inhibition of BMP, Wnt, and retinoic acid signaling. Noto-GFP(+) cells expressed the node/notochord markers Noto, Foxa2, Shh, Noggin, Chordin, Foxj1, and Brachyury; showed a vacuolarization characteristic of notochord cells; and can integrate into midline structures when grafted into Hensen's node of gastrulating chicken embryos. The ability to generate node/notochord-like cells in vitro will aid the biochemical characterization of these developmentally important structures.

Zeb1-Hdac2-eNOS circuitry identifies early cardiovascular precursors in naive mouse embryonic stem cells.

PubMed

Cencioni, Chiara; Spallotta, Francesco; Savoia, Matteo; Kuenne, Carsten; Guenther, Stefan; Re, Agnese; Wingert, Susanne; Rehage, Maike; Sürün, Duran; Siragusa, Mauro; Smith, Jacob G; Schnütgen, Frank; von Melchner, Harald; Rieger, Michael A; Martelli, Fabio; Riccio, Antonella; Fleming, Ingrid; Braun, Thomas; Zeiher, Andreas M; Farsetti, Antonella; Gaetano, Carlo

2018-03-29

Nitric oxide (NO) synthesis is a late event during differentiation of mouse embryonic stem cells (mESC) and occurs after release from serum and leukemia inhibitory factor (LIF). Here we show that after release from pluripotency, a subpopulation of mESC, kept in the naive state by 2i/LIF, expresses endothelial nitric oxide synthase (eNOS) and endogenously synthesizes NO. This eNOS/NO-positive subpopulation (ESNO+) expresses mesendodermal markers and is more efficient in the generation of cardiovascular precursors than eNOS/NO-negative cells. Mechanistically, production of endogenous NO triggers rapid Hdac2 S-nitrosylation, which reduces association of Hdac2 with the transcriptional repression factor Zeb1, allowing mesendodermal gene expression. In conclusion, our results suggest that the interaction between Zeb1, Hdac2, and eNOS is required for early mesendodermal differentiation of naive mESC.

Chondroitin Sulfate Is Indispensable for Pluripotency and Differentiation of Mouse Embryonic Stem Cells

NASA Astrophysics Data System (ADS)

Izumikawa, Tomomi; Sato, Ban; Kitagawa, Hiroshi

2014-01-01

Chondroitin sulfate (CS) proteoglycans are present on the surfaces of virtually all cells and in the extracellular matrix and are required for cytokinesis at early developmental stages. Studies have shown that heparan sulfate (HS) is essential for maintaining mouse embryonic stem cells (ESCs) that are primed for differentiation, whereas the function of CS has not yet been elucidated. To clarify the role of CS, we generated glucuronyltransferase-I-knockout ESCs lacking CS. We found that CS was required to maintain the pluripotency of ESCs and promoted initial ESC commitment to differentiation compared with HS. In addition, CS-A and CS-E polysaccharides, but not CS-C polysaccharides, bound to E-cadherin and enhanced ESC differentiation. Multiple-lineage differentiation was inhibited in chondroitinase ABC-digested wild-type ESCs. Collectively, these results suggest that CS is a novel determinant in controlling the functional integrity of ESCs via binding to E-cadherin.

Spontaneous generation of germline characteristics in mouse fibrosarcoma cells

NASA Astrophysics Data System (ADS)

Ma, Zhan; Hu, Yao; Jiang, Guoying; Hou, Jun; Liu, Ruilai; Lu, Yuan; Liu, Chunfang

2012-10-01

Germline/embryonic-specific genes have been found to be activated in somatic tumors. In this study, we further showed that cells functioning as germline could be present in mouse fibrosarcoma cells (L929 cell line). Early germline-like cells spontaneously appeared in L929 cells and further differentiated into oocyte-like cells. These germline-like cells can, in turn, develop into blastocyst-like structures in vitro and cause teratocarcinomas in vivo, which is consistent with natural germ cells in function. Generation of germline-like cells from somatic tumors might provide a novel way to understand why somatic cancer cells have strong features of embryonic/germline development. It is thought that the germline traits of tumors are associated with the central characteristics of malignancy, such as immortalization, invasion, migration and immune evasion. Therefore, germline-like cells in tumors might provide potential targets to tumor biology, diagnosis and therapy.

ChIP-seq Identification of Weakly Conserved Heart Enhancers

PubMed Central

Blow, Matthew J.; McCulley, David J.; Li, Zirong; Zhang, Tao; Akiyama, Jennifer A.; Holt, Amy; Plajzer-Frick, Ingrid; Shoukry, Malak; Wright, Crystal; Chen, Feng; Afzal, Veena; Bristow, James; Ren, Bing; Black, Brian L.; Rubin, Edward M.; Visel, Axel; Pennacchio, Len A.

2011-01-01

Accurate control of tissue-specific gene expression plays a pivotal role in heart development, but few cardiac transcriptional enhancers have thus far been identified. Extreme non-coding sequence conservation successfully predicts enhancers active in many tissues, but fails to identify substantial numbers of heart enhancers. Here we used ChIP-seq with the enhancer-associated protein p300 from mouse embryonic day 11.5 heart tissue to identify over three thousand candidate heart enhancers genome-wide. Compared to other tissues studied at this time-point, most candidate heart enhancers are less deeply conserved in vertebrate evolution. Nevertheless, the testing of 130 candidate regions in a transgenic mouse assay revealed that most of them reproducibly function as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for a large population of poorly conserved heart enhancers and suggest that the evolutionary constraint of embryonic enhancers can vary depending on tissue type. PMID:20729851

Isolation and Characterization of Node/Notochord-Like Cells from Mouse Embryonic Stem Cells

PubMed Central

Winzi, Maria K.; Hyttel, Poul; Dale, Jacqueline Kim; Serup, Palle

2014-01-01

The homeobox gene Noto is expressed in the node and its derivative the notochord. Here we use a targeted Noto-GFP reporter to isolate and characterize node/notochord-like cells derived from mouse embryonic stem cells. We find very few Noto-expressing cells after spontaneous differentiation. However, the number of Noto-expressing cells was increased when using Activin A to induce a Foxa2- and Brachyury-expressing progenitor population, whose further differentiation into Noto-expressing cells was improved by simultaneous inhibition of BMP, Wnt, and retinoic acid signaling. Noto-GFP+ cells expressed the node/notochord markers Noto, Foxa2, Shh, Noggin, Chordin, Foxj1, and Brachyury; showed a vacuolarization characteristic of notochord cells; and can integrate into midline structures when grafted into Hensen’s node of gastrulating chicken embryos. The ability to generate node/notochord-like cells in vitro will aid the biochemical characterization of these developmentally important structures. PMID:21351873

[Effect of Panax ginseng components on the differentiation of mouse embryonic stem cells into cardiac-like cells].

PubMed

Sasaki, Toshiya; Oh, Ki-Bong; Matsuoka, Hideaki; Saito, Mikako

2008-03-01

Bioactive compounds that may control the specific differentiation from mouse embryonic stem (ES) cells into cardiac-like cells have been screened from herbal medicines. Among seven preparations, Panax ginseng was found to promote the differentiation into beating cells and to sustain their beating for longer than the control. Active compounds were found in its water-soluble fraction. Although they were not isolated, their candidates were surveyed in 42 compounds selected from the database of P. ginseng. Finally we found that vitamin B12 (VB12) and methionine were active. VB12 accelerated the differentiation into beating cells and made the beating rate constantly 100%. Moreover, VB12 was effective in the recovery of beating that was inhibited by spermine action. The mechanism of action of VB12 is discussed in termo of the relevance of intercellular electrical signal transduction.

Differentiated NSC-34 cells as an in vitro Cell Model for VX

DTIC Science & Technology

2014-09-11

potential candidate drugs/antidotes. The development of an in vitro cellular model to aid in discovering new NA therapeutics would be highly beneficial...principally as potent cholinesterase inhibitors. The toxicity of these compounds and their mode of action are attributed to the inhibition of the enzyme ...of motor neuron- enriched, embryonic mouse spinal cord cells with mouse neuroblastoma as a potential neuronal model (Durham et al., 1993). This cell

Parthenogenesis-derived Multipotent Stem Cells Adapted for Tissue Engineering Applications

PubMed Central

Koh, Chester J.; Delo, Dawn M.; Lee, Jang Won; Siddiqui, M. Minhaj; Lanza, Robert P.; Soker, Shay; Yoo, James J.; Atala, Anthony

2009-01-01

Embryonic stem cells are envisioned as a viable source of pluripotent cells for use in regenerative medicine applications when donor tissue is not available. However, most current harvest techniques for embryonic stem cells require the destruction of embryos, which has led to significant political and ethical limitations on their usage. Parthenogenesis, the process by which an egg can develop into an embryo in the absence of sperm, may be a potential source of embryonic stem cells that may avoid some of the political and ethical concerns surrounding embryonic stem cells. Here we provide the technical aspects of embryonic stem cell isolation and expansion from the parthenogenetic activation of oocytes. These cells were characterized for their stem-cell properties. In addition, these cells were induced to differentiate to the myogenic, osteogenic, adipogenic, and endothelial lineages, and were able to form muscle-like and bony-like tissue in vivo. Furthermore, parthenogenetic stem cells were able to integrate into injured muscle tissue. Together, these results demonstrate that parthenogenetic stem cells can be successfully isolated and utilized for various tissue engineering applications. PMID:18799133

3D bioprinting of biomimetic aortic vascular constructs with self-supporting cells.

PubMed

Kucukgul, Can; Ozler, S Burce; Inci, Ilyas; Karakas, Ezgi; Irmak, Ster; Gozuacik, Devrim; Taralp, Alpay; Koc, Bahattin

2015-04-01

Cardiovascular diseases are the leading cause of deaths throughout the world. Vascular diseases are mostly treated with autografts and blood vessel transplantations. However, traditional grafting methods have several problems including lack of suitable harvest sites, additional surgical costs for harvesting procedure, pain, infection, lack of donors, and even no substitutes at all. Recently, tissue engineering and regenerative medicine approaches are used to regenerate damaged or diseased tissues. Most of the tissue engineering investigations have been based on the cell seeding into scaffolds by providing a suitable environment for cell attachment, proliferation, and differentiation. Because of the challenges such as difficulties in seeding cells spatially, rejection, and inflammation of biomaterials used, the recent tissue engineering studies focus on scaffold-free techniques. In this paper, the development of novel computer aided algorithms and methods are developed for 3D bioprinting of scaffold-free biomimetic macrovascular structures. Computer model mimicking a real human aorta is generated using imaging techniques and the proposed computational algorithms. An optimized three-dimensional bioprinting path planning are developed with the proposed self-supported model. Mouse embryonic fibroblast (MEF) cell aggregates and support structures (hydrogels) are 3D bioprinted layer-by-layer according to the proposed self-supported method to form an aortic tissue construct. © 2014 Wiley Periodicals, Inc.

Functional characterization of human pluripotent stem cell-derived arterial endothelial cells.

PubMed

Zhang, Jue; Chu, Li-Fang; Hou, Zhonggang; Schwartz, Michael P; Hacker, Timothy; Vickerman, Vernella; Swanson, Scott; Leng, Ning; Nguyen, Bao Kim; Elwell, Angela; Bolin, Jennifer; Brown, Matthew E; Stewart, Ron; Burlingham, William J; Murphy, William L; Thomson, James A

2017-07-25

Here, we report the derivation of arterial endothelial cells from human pluripotent stem cells that exhibit arterial-specific functions in vitro and in vivo. We combine single-cell RNA sequencing of embryonic mouse endothelial cells with an EFNB2-tdTomato/EPHB4-EGFP dual reporter human embryonic stem cell line to identify factors that regulate arterial endothelial cell specification. The resulting xeno-free protocol produces cells with gene expression profiles, oxygen consumption rates, nitric oxide production levels, shear stress responses, and TNFα-induced leukocyte adhesion rates characteristic of arterial endothelial cells. Arterial endothelial cells were robustly generated from multiple human embryonic and induced pluripotent stem cell lines and have potential applications for both disease modeling and regenerative medicine.

Human amniotic epithelial cells as feeder layer to derive and maintain human embryonic stem cells from poor-quality embryos.

PubMed

Ávila-González, Daniela; Vega-Hernández, Eva; Regalado-Hernández, Juan Carlos; De la Jara-Díaz, Julio Francisco; García-Castro, Irma Lydia; Molina-Hernández, Anayansi; Moreno-Verduzco, Elsa Romelia; Razo-Aguilera, Guadalupe; Flores-Herrera, Héctor; Portillo, Wendy; Díaz-Martínez, Néstor Emmanuel; García-López, Guadalupe; Díaz, Néstor Fabián

2015-09-01

Data from the literature suggest that human embryonic stem cell (hESC) lines used in research do not genetically represent all human populations. The derivation of hESC through conventional methods involve the destruction of viable human embryos, as well the use of mouse embryonic fibroblasts as a feeder layer, which has several drawbacks. We obtained the hESC line (Amicqui-1) from poor-quality (PQ) embryos derived and maintained on human amniotic epithelial cells (hAEC). This line displays a battery of markers of pluripotency and we demonstrated the capacity of these cells to produce derivates of the three germ layers. Copyright © 2015. Published by Elsevier B.V.

Next generation tools for high-throughput promoter and expression analysis employing single-copy knock-ins at the Hprt1 locus.

PubMed

Yang, G S; Banks, K G; Bonaguro, R J; Wilson, G; Dreolini, L; de Leeuw, C N; Liu, L; Swanson, D J; Goldowitz, D; Holt, R A; Simpson, E M

2009-03-01

We have engineered a set of useful tools that facilitate targeted single copy knock-in (KI) at the hypoxanthine guanine phosphoribosyl transferase 1 (Hprt1) locus. We employed fine scale mapping to delineate the precise breakpoint location at the Hprt1(b-m3) locus allowing allele specific PCR assays to be established. Our suite of tools contains four targeting expression vectors and a complementing series of embryonic stem cell lines. Two of these vectors encode enhanced green fluorescent protein (EGFP) driven by the human cytomegalovirus immediate-early enhancer/modified chicken beta-actin (CAG) promoter, whereas the other two permit flexible combinations of a chosen promoter combined with a reporter and/or gene of choice. We have validated our tools as part of the Pleiades Promoter Project (http://www.pleiades.org), with the generation of brain-specific EGFP positive germline mouse strains.

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis

PubMed Central

Tosetti, Valentina; Sassone, Jenny; Ferri, Anna L. M.; Taiana, Michela; Bedini, Gloria; Nava, Sara; Brenna, Greta; Di Resta, Chiara; Pareyson, Davide; Di Giulio, Anna Maria; Carelli, Stephana

2017-01-01

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT. PMID:28704421

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis.

PubMed

Tosetti, Valentina; Sassone, Jenny; Ferri, Anna L M; Taiana, Michela; Bedini, Gloria; Nava, Sara; Brenna, Greta; Di Resta, Chiara; Pareyson, Davide; Di Giulio, Anna Maria; Carelli, Stephana; Parati, Eugenio A; Gorio, Alfredo

2017-01-01

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT.

Fluid shear stress primes mouse embryonic stem cells for differentiation in a self-renewing environment via heparan sulfate proteoglycans transduction

PubMed Central

Toh, Yi-Chin; Voldman, Joel

2011-01-01

Shear stress is a ubiquitous environmental cue experienced by stem cells when they are being differentiated or expanded in perfusion cultures. However, its role in modulating self-renewing stem cell phenotypes is unclear, since shear is usually only studied in the context of cardiovascular differentiation. We used a multiplex microfluidic array, which overcomes the limitations of macroperfusion systems in shear application throughput and precision, to initiate a comprehensive, quantitative study of shear effects on self-renewing mouse embryonic stem cells (mESCs), where shear stresses varying by >1000 times (0.016–16 dyn/cm2) are applied simultaneously. When compared with static controls in the presence or absence of a saturated soluble environment (i.e., mESC-conditioned medium), we ascertained that flow-induced shear stress specifically up-regulates the epiblast marker Fgf5. Epiblast-state transition in mESCs involves heparan sulfate proteoglycans (HSPGs), which have also been shown to transduce shear stress in endothelial cells. By disrupting (with sulfation inhibitors and heparinase) and partially reconstituting (with heparin) HSPG function, we show that mESCs also mechanically sense shear stress via HSPGs to modulate Fgf5 expression. This study demonstrates that self-renewing mESCs possess the molecular machinery to sense shear stress and provides quantitative shear application benchmarks for future scalable stem cell culture systems.—Toh, Y.-C., Voldman, J. Fluid shear stress primes mouse embryonic stem cells for differentiation in a self-renewing environment via heparan sulfate proteoglycans transduction. PMID:21183594

Effects of low-dose γ-rays on the embryonic development of mouse melanoblasts and melanocytes in the epidermis and hair bulbs.

PubMed

Hirobe, Tomohisa; Eguchi-Kasai, Kiyomi; Sugaya, Kimihiko; Murakami, Masahiro

2011-06-01

The effects of low-dose γ-rays on the embryonic development of animal cells are not well studied. The mouse melanocyte is a good model to study the effects of low-dose γ-rays on the development of animal cells, as it possesses visible pigment (melanin) as a differentiation marker. The aim of this study is to investigate in detail the effects of low-dose γ-rays on embryonic development of mouse melanoblasts and melanocytes in the epidermis and hair bulbs at cellular level. Pregnant females of C57BL/10J mice at nine days of gestation were whole-body irradiated with a single acute dose of γrays (0.1, 0.25, 0.5, and 0.75 Gy), and the effects of γ-rays were studied by scoring changes in the development of epidermal melanoblasts and melanocytes, hair follicles, and hair bulb melanocytes at 18 days in gestation. The number of epidermal melanoblasts and melanocytes, hair follicles, and hair bulb melanocytes in the dorsal and ventral skins was markedly decreased even at 0.1 Gy-treated embryos (P < 0.001), and gradually decreased as dose increased. The effects on the ventral skin were greater than those on the dorsal skin. The dramatic reduction in the number of melanocytes compared to melanoblasts was observed in the ventral skin, but not in the dorsal skin. These results suggest that low-dose γ-rays provoke the death of melanoblasts and melanocytes, or inhibit the proliferation and differentiation of melanoblasts and melanocytes, even at the low dose.

The forkhead box m1 transcription factor is essential for embryonic development of pulmonary vasculature.

PubMed

Kim, Il-Man; Ramakrishna, Sneha; Gusarova, Galina A; Yoder, Helena M; Costa, Robert H; Kalinichenko, Vladimir V

2005-06-10

Transgenic and gene knock-out studies demonstrated that the mouse Forkhead Box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) is essential for hepatocyte entry into mitosis during liver development, regeneration, and liver cancer. Targeted deletion of Foxm1 gene in mice produces an embryonic lethal phenotype due to severe abnormalities in the development of liver and heart. In this study, we show for the first time that Foxm1(-/-) lungs exhibit severe hypertrophy of arteriolar smooth muscle cells and defects in the formation of peripheral pulmonary capillaries as evidenced by significant reduction in platelet endothelial cell adhesion molecule 1 staining of the distal lung. Consistent with these findings, significant reduction in proliferation of the embryonic Foxm1(-/-) lung mesenchyme was found, yet proliferation levels were normal in the Foxm1-deficient epithelial cells. Severe abnormalities of the lung vasculature in Foxm1(-/-) embryos were associated with diminished expression of the transforming growth factor beta receptor II, a disintegrin and metalloprotease domain 17 (ADAM-17), vascular endothelial growth factor receptors, Polo-like kinase 1, Aurora B kinase, laminin alpha4 (Lama4), and the Forkhead Box f1 transcription factor. Cotransfection studies demonstrated that Foxm1 stimulates transcription of the Lama4 promoter, and this stimulation requires the Foxm1 binding sites located between -1174 and -1145 bp of the mouse Lama4 promoter. In summary, development of mouse lungs depends on the Foxm1 transcription factor, which regulates expression of genes essential for mesenchyme proliferation, extracellular matrix remodeling, and vasculogenesis.

High-throughput identification of small molecules that affect human embryonic vascular development

PubMed Central

Vazão, Helena; Rosa, Susana; Barata, Tânia; Costa, Ricardo; Pitrez, Patrícia R.; Honório, Inês; de Vries, Margreet R.; Papatsenko, Dimitri; Benedito, Rui; Saris, Daniel; Khademhosseini, Ali; Quax, Paul H. A.; Pereira, Carlos F.; Mercader, Nadia; Ferreira, Lino

2017-01-01

Birth defects, which are in part caused by exposure to environmental chemicals and pharmaceutical drugs, affect 1 in every 33 babies born in the United States each year. The current standard to screen drugs that affect embryonic development is based on prenatal animal testing; however, this approach yields low-throughput and limited mechanistic information regarding the biological pathways and potential adverse consequences in humans. To develop a screening platform for molecules that affect human embryonic development based on endothelial cells (ECs) derived from human pluripotent stem cells, we differentiated human pluripotent stem cells into embryonic ECs and induced their maturation under arterial flow conditions. These cells were then used to screen compounds that specifically affect embryonic vasculature. Using this platform, we have identified two compounds that have higher inhibitory effect in embryonic than postnatal ECs. One of them was fluphenazine (an antipsychotic), which inhibits calmodulin kinase II. The other compound was pyrrolopyrimidine (an antiinflammatory agent), which inhibits vascular endothelial growth factor receptor 2 (VEGFR2), decreases EC viability, induces an inflammatory response, and disrupts preformed vascular networks. The vascular effect of the pyrrolopyrimidine was further validated in prenatal vs. adult mouse ECs and in embryonic and adult zebrafish. We developed a platform based on human pluripotent stem cell-derived ECs for drug screening, which may open new avenues of research for the study and modulation of embryonic vasculature. PMID:28348206

High-throughput identification of small molecules that affect human embryonic vascular development.

PubMed

Vazão, Helena; Rosa, Susana; Barata, Tânia; Costa, Ricardo; Pitrez, Patrícia R; Honório, Inês; de Vries, Margreet R; Papatsenko, Dimitri; Benedito, Rui; Saris, Daniel; Khademhosseini, Ali; Quax, Paul H A; Pereira, Carlos F; Mercader, Nadia; Fernandes, Hugo; Ferreira, Lino

2017-04-11

Birth defects, which are in part caused by exposure to environmental chemicals and pharmaceutical drugs, affect 1 in every 33 babies born in the United States each year. The current standard to screen drugs that affect embryonic development is based on prenatal animal testing; however, this approach yields low-throughput and limited mechanistic information regarding the biological pathways and potential adverse consequences in humans. To develop a screening platform for molecules that affect human embryonic development based on endothelial cells (ECs) derived from human pluripotent stem cells, we differentiated human pluripotent stem cells into embryonic ECs and induced their maturation under arterial flow conditions. These cells were then used to screen compounds that specifically affect embryonic vasculature. Using this platform, we have identified two compounds that have higher inhibitory effect in embryonic than postnatal ECs. One of them was fluphenazine (an antipsychotic), which inhibits calmodulin kinase II. The other compound was pyrrolopyrimidine (an antiinflammatory agent), which inhibits vascular endothelial growth factor receptor 2 (VEGFR2), decreases EC viability, induces an inflammatory response, and disrupts preformed vascular networks. The vascular effect of the pyrrolopyrimidine was further validated in prenatal vs. adult mouse ECs and in embryonic and adult zebrafish. We developed a platform based on human pluripotent stem cell-derived ECs for drug screening, which may open new avenues of research for the study and modulation of embryonic vasculature.

Flt1/VEGFR1 heterozygosity causes transient embryonic edema.

PubMed

Otowa, Yasunori; Moriwaki, Kazumasa; Sano, Keigo; Shirakabe, Masanori; Yonemura, Shigenobu; Shibuya, Masabumi; Rossant, Janet; Suda, Toshio; Kakeji, Yoshihiro; Hirashima, Masanori

2016-06-02

Vascular endothelial growth factor-A is a major player in vascular development and a potent vascular permeability factor under physiological and pathological conditions by binding to a decoy receptor Flt1 and its primary receptor Flk1. In this study, we show that Flt1 heterozygous (Flt1(+/-)) mouse embryos grow up to adult without life-threatening abnormalities but exhibit a transient embryonic edema around the nuchal and back regions, which is reminiscent of increased nuchal translucency in human fetuses. Vascular permeability is enhanced and an intricate infolding of the plasma membrane and huge vesicle-like structures are seen in Flt1(+/-) capillary endothelial cells. Flk1 tyrosine phosphorylation is elevated in Flt1(+/-) embryos, but Flk1 heterozygosity does not suppress embryonic edema caused by Flt1 heterozygosity. When Flt1 mutants are crossed with Aspp1(-/-) mice which exhibit a transient embryonic edema with delayed formation and dysfunction of lymphatic vessels, only 5.7% of Flt1(+/-); Aspp1(-/-) mice survive, compared to expected ratio (25%). Our results demonstrate that Flt1 heterozygosity causes a transient embryonic edema and can be a risk factor for embryonic lethality in combination with other mutations causing non-lethal vascular phenotype.

Locust bean gum as an alternative polymeric coating for embryonic stem cell culture.

PubMed

Perestrelo, Ana Rubina; Grenha, Ana; Rosa da Costa, Ana M; Belo, José António

2014-07-01

Pluripotent embryonic stem cells (ESCs) have self-renewal capacity and the potential to differentiate into any cellular type depending on specific cues (pluripotency) and, therefore, have become a vibrant research area in the biomedical field. ESCs are usually cultured in gelatin or on top of a monolayer of feeder cells such as mitotically inactivated mouse embryonic fibroblasts (MEFsi). The latter is the gold standard support to maintain the ESCs in the pluripotent state. Examples of versatile, non-animal derived and inexpensive materials that are able to support pluripotent ESCs are limited. Therefore, our aim was to find a biomaterial able to support ESC growth in a pluripotent state avoiding laborious and time consuming parallel culture of MEFsi and as simple to handle as gelatin. Many of the new biomaterials used to develop stem cell microenvironments are using natural polymers adsorbed or covalently attached to the surface to improve the biocompatibility of synthetic polymers. Locust beam gum (LBG) is a natural, edible polymer, which has a wide range of potential applications in different fields, such as food and pharmaceutical industry, due to its biocompatibility, adhesiveness and thickening properties. The present work brings a natural system based on the use of LBG as a coating for ESC culture. Undifferentiated mouse ESCs were cultured on commercially available LBG to evaluate its potential in maintaining pluripotent ESCs. In terms of morphology, ESC colonies in LBG presented the regular dome shape with bright borders, similar to the colonies obtained in co-cultures with MEFsi and characteristic of pluripotent ESC colonies. In short-term cultures, ESC proliferation in LBG coating was similar to ESC cultured in gelatin and the cells maintained their viability. The activity of alkaline phosphatase and Nanog, Sox2 and Oct4 expression of mouse ESCs cultured in LBG were comparable or in some cases higher than in ESCs cultured in gelatin. An in vitro differentiation assay revealed that mouse ESCs cultured in LBG preserve their tri-lineage differentiation capacity. In conclusion, our data indicate that LBG coating promotes mouse ESC growth in an undifferentiated state demonstrating to be a viable, non-animal derived alternative to gelatin to support pluripotent mouse ESCs in culture. Copyright © 2014 Elsevier B.V. All rights reserved.

Bridging the gap: functional healing of embryonic small intestine ex vivo

PubMed Central

Coletta, Riccardo; Roberts, Neil A.; Oltrabella, Francesca; Khalil, Basem A.; Morabito, Antonino

2015-01-01

Abstract The ability to grow embryonic organs ex vivo provides an opportunity to follow their differentiation in a controlled environment, with resulting insights into normal development. Additionally, similar strategies can be used to assess effects on organogenesis of physical and chemical manipulations. This study aimed to create an organ culture model with which to test physical manipulations to enhance healing of gut segments, thus generating a single functional organ. Embryonic mouse jejunum was isolated and cut into 2–3 mm tubes, which were placed in pairs, separated by a small gap, on semi‐permeable supports. Each pair was linked by a nylon suture threaded through their lumens. After 3 days in organ culture fed by defined serum‐free media, the rudiments differentiated to form tubes of smooth muscle surrounding a core of rudimentary villi. Of 34 such pairs, 74% had touching and well aligned proximate ends. Of these joined structures, 80% (59% of the total pairs) had a continuous lumen, as assessed by observing the trajectories of fluorescent dextrans injected into their distal ends. Fused organ pairs formed a single functional unit, as assessed by spontaneous contraction waves propagated along their lengths. In these healed intestines, peripherin+ neurons formed a nexus in the zone of fusion, linking the rudiment pairs. In future, this system could be used to test whether growth factors enhance fusion. Such results should in turn inform the design of novel treatments for short bowel syndrome, a potentially fatal condition with a currently limited and imperfect range of therapies. ©2015. The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd PMID:26234729

Development of experimental tumors formed by mouse and human embryonic stem and teratocarcinoma cells after subcutaneous and intraperitoneal transplantations into immunodeficient and immunocompetent mice.

PubMed

Gordeeva, O F; Nikonova, T M

2013-01-01

Pluripotent stem cells represent an attractive cell source for regenerative medicine. However, the risk of teratoma formation after transplantation restricts their clinical application. Therefore, to adequately evaluate the potential risk of tumorigenicity after cell transplantation into human tissues, effective animal transplantation assays need to be developed. We performed a multiparameter (cell number, transplantation site, cell type, host) comparative analysis of the efficiency of tumor development after transplantation of mouse and human embryonic stem (ES) cells and their malignant counterparts, teratocarcinoma (EC) cells, into animal recipients and revealed several key correlations. We found that the efficiency of tumor growth was higher after intraperitoneal than after subcutaneous transplantations of all cell lines studied. The minimal cell numbers sufficient for tumor growth in immunodeficient nude mice were 100-fold lower for intraperitoneal than for subcutaneous transplantations of mouse and human ES cells (10(3) vs. 10(5) and 10(4) vs. 10(6), respectively). Moreover, mouse ES and EC cells formed tumors in immunodeficient and immunocompetent mice more effectively than human ES and EC cells. After intraperitoneal transplantation of 10(3), 10(4), and 10(5) mouse ES cells, teratomas developed in 83%, 100%, and 100% of nude mice, whereas after human ES cell transplantation, teratomas developed in 0%, 17%, and 60%, respectively. In addition, malignant mouse and human EC cells initiated tumor growth after intraperitoneal transplantation significantly faster and more effectively than ES cells. Mouse and human ES cells formed different types of teratomas containing derivatives of three germ layers but different numbers of undifferentiated cells. ES cell-like sublines with differentiation potential similar to the parental cell line were recloned only from mouse, but not from human, ES cell teratomas. These findings provide new information about the possibility and efficiency of tumor growth after transplantation of pluripotent stem cells. This information allows one to predict and possibly prevent the possible risks of tumorigenicity that could arise from stem cell therapeutics.

The expression and crucial roles of BMP signaling in development of smooth muscle progenitor cells in the mouse embryonic gut.

PubMed

Torihashi, Shigeko; Hattori, Takako; Hasegawa, Hirotaka; Kurahashi, Masaaki; Ogaeri, Takunori; Fujimoto, Toyoshi

2009-03-01

Bone morphogenetic protein (BMP) signaling is essential for normal development of the gastrointestinal (GI) tract. BMPs also play multiple roles in vascular smooth muscle cells; however, the BMP signaling in the development of the GI musculature remains to be clarified. We investigated the expression of BMPs and their receptors in mouse embryonic GI tracts by immunohistochemistry and in situ hybridization. We demonstrated that BMP2, BMP receptor Ib and BMP receptor II were expressed in the smooth muscle progenitors from E12 to E13 for the first time. BMP signaling on smooth muscle differentiation was examined by implantation of agarose beads soaked with BMPs in the in vitro developmental model that is gut-like structures from mouse embryonic stem (ES) cells. BMP2 rather than BMP4 beads enhanced smooth muscle differentiation, and increased gut-like structures showing spontaneous contractions and expressing intensive alpha-smooth muscle actin immunoreactivity. This increase was confirmed by up-regulation of SM22 mRNA shown by real-time PCR. By addition of noggin beads or noggin to the medium at BMP2 bead implantation, the ratio of contractive gut-like structures decreased. Implantation of BMP2 beads at EB7 (EB--embryoid bodies) (corresponding to E12 or E13 of mouse embryo) showed the highest effects and up-regulation of transcription factors msx-1 after 24h. This increase was blocked by noggin, and msx-1 decreased to almost the control level after 60 h. BMP2 beads at EB7 increased platelet-derived growth factor-A (PDGF-A) in the differentiating smooth muscle cells. We have recently reported that PDGF-A is expressed in the developing inner circular smooth muscle and is crucial for the longitudinal smooth muscle differentiation. Taken together, BMP signaling was expressed for a short window in the smooth muscle progenitors and the signal, especially BMP2, plays an essential role in smooth muscle differentiation in cooperation with PDGF signaling.

Mutation of SIMPLE in Charcot–Marie–Tooth 1C alters production of exosomes

PubMed Central

Zhu, Hong; Guariglia, Sara; Yu, Raymond Y. L.; Li, Wenjing; Brancho, Deborah; Peinado, Hector; Lyden, David; Salzer, James; Bennett, Craig; Chow, Chi-Wing

2013-01-01

Charcot–Marie–Tooth (CMT) disease is an inherited neurological disorder. Mutations in the small integral membrane protein of the lysosome/late endosome (SIMPLE) account for the rare autosomal-dominant demyelination in CMT1C patients. Understanding the molecular basis of CMT1C pathogenesis is impeded, in part, by perplexity about the role of SIMPLE, which is expressed in multiple cell types. Here we show that SIMPLE resides within the intraluminal vesicles of multivesicular bodies (MVBs) and inside exosomes, which are nanovesicles secreted extracellularly. Targeting of SIMPLE to exosomes is modulated by positive and negative regulatory motifs. We also find that expression of SIMPLE increases the number of exosomes and secretion of exosome proteins. We engineer a point mutation on the SIMPLE allele and generate a physiological mouse model that expresses CMT1C-mutated SIMPLE at the endogenous level. We find that CMT1C mouse primary embryonic fibroblasts show decreased number of exosomes and reduced secretion of exosome proteins, in part due to improper formation of MVBs. CMT1C patient B cells and CMT1C mouse primary Schwann cells show similar defects. Together the data indicate that SIMPLE regulates the production of exosomes by modulating the formation of MVBs. Dysregulated endosomal trafficking and changes in the landscape of exosome-mediated intercellular communications may place an overwhelming burden on the nervous system and account for CMT1C molecular pathogenesis. PMID:23576546

Integrin αIIb (CD41) plays a role in the maintenance of hematopoietic stem cell activity in the mouse embryonic aorta

PubMed Central

Boisset, Jean-Charles; Clapes, Thomas; Van Der Linden, Reinier; Dzierzak, Elaine; Robin, Catherine

2013-01-01

Summary Integrins are transmembrane receptors that play important roles as modulators of cell behaviour through their adhesion properties and the initiation of signaling cascades. The αIIb integrin subunit (CD41) is one of the first cell surface markers indicative of hematopoietic commitment. αIIb pairs exclusively with β3 to form the αIIbβ3 integrin. β3 (CD61) also pairs with αv (CD51) to form the αvβ3 integrin. The expression and putative role of these integrins during mouse hematopoietic development is as yet unknown. We show here that hematopoietic stem cells (HSCs) differentially express αIIbβ3 and αvβ3 integrins throughout development. Whereas the first HSCs generated in the aorta at mid-gestation express both integrins, HSCs from the placenta only express αvβ3, and most fetal liver HSCs do not express either integrin. By using αIIb deficient embryos, we show that αIIb is not only a reliable HSC marker but it also plays an important and specific function in maintaining the HSC activity in the mouse embryonic aorta. PMID:23789102

Altered social behavior and neuronal development in mice lacking the Uba6-Use1 ubiquitin transfer system

PubMed Central

Lee, Peter C. W.; Dodart, Jean-Cosme; Aron, Liviu; Finley, Lydia W.; Bronson, Roderick T.; Haigis, Marcia C.; Yankner, Bruce A.; Harper, J. Wade

2013-01-01

The Uba6 (E1)-Use1 (E2) ubiquitin transfer cascade is a poorly understood alternative arm of the ubiquitin proteasome system (UPS) required for mouse embryonic development, independent of the canonical Uba1-E2-E3 pathway. Loss of neuronal Uba6 during embryonic development results in altered patterning of neurons in the hippocampus and the amygdala, decreased dendritic spine density, and numerous behavioral disorders. The levels of the E3 ubiquitin ligase Ube3a (E6-AP) and Shank3, both linked with dendritic spine function, are elevated in the amygdala of Uba6-deficient mice, while levels of the Ube3a substrate Arc are reduced. Uba6 and Use1 promote proteasomal turnover of Ube3a in mouse embryo fibroblasts (MEFs) and catalyze Ube3a ubiquitylation in vitro. These activities occur in parallel with an independent pathway involving Uba1-UbcH7, but in a spatially distinct manner in MEFs. These data reveal an unanticipated role for Uba6 in neuronal development, spine architecture, mouse behavior, and turnover of Ube3a. PMID:23499007

In situ electrochemical detection of embryonic stem cell differentiation.

PubMed

Yea, Cheol-Heon; An, Jeung Hee; Kim, Jungho; Choi, Jeong-Woo

2013-06-20

Stem cell sensors have emerged as a promising technique to electrochemically monitor the functional status and viability of stem cells. However, efficient electrochemical analysis techniques are required for the development of effective electrochemical stem cell sensors. In the current study, we report a newly developed electrochemical cyclic voltammetry (CV) system to determine the status of mouse embryonic stem (ES) cells. 1-Naphthly phosphate (1-NP), which was dephosphorylated by alkaline phosphatase into a 1-naphthol on an undifferentiated mouse ES cell, was used as a substrate to electrochemically monitor the differentiation status of mouse ES cells. The peak current in the cyclic voltammetry of 1-NP increased linearly with the concentration of pure 1-NP (R(2)=0.9623). On the other hand, the peak current in the electrochemical responses of 1-NP decreased as the number of undifferentiated ES cells increased. The increased dephosphorylation of 1-NP to 1-naphthol made a decreased electrochemical signal. Non-toxicity of 1-NP was confirmed. In conclusion, the proposed electrochemical analysis system can be applied to an electrical stem cell chip for diagnosis, drug detection and on-site monitoring. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of hollow fiber culture for large-scale production of mouse embryonic stem cell-derived hematopoietic stem cells.

PubMed

Nakano, Yu; Iwanaga, Shinya; Mizumoto, Hiroshi; Kajiwara, Toshihisa

2018-03-03

Hematopoietic stem cells (HSCs) have the ability to differentiate into all types of blood cells and can be transplanted to treat blood disorders. However, it is difficult to obtain HSCs in large quantities because of the shortage of donors. Recent efforts have focused on acquiring HSCs by differentiation of pluripotent stem cells. As a conventional differentiation method of pluripotent stem cells, the formation of embryoid bodies (EBs) is often employed. However, the size of EBs is limited by depletion of oxygen and nutrients, which prevents them from being efficient for the production of HSCs. In this study, we developed a large-scale hematopoietic differentiation approach for mouse embryonic stem (ES) cells by applying a hollow fiber (HF)/organoid culture method. Cylindrical organoids, which had the potential for further spontaneous differentiation, were established inside of hollow fibers. Using this method, we improved the proliferation rate of mouse ES cells to produce an increased HSC population and achieved around a 40-fold higher production volume of HSCs in HF culture than in conventional EB culture. Therefore, the HF/organoid culture method may be a new mass culture method to acquire pluripotent stem cell-derived HSCs.

Structural organization and chromosomal assignment of the mouse embryonic TEA domain-containing factor (ETF) gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Kazuo; Yasunami, Michio; Matsuda, Yoichi

1996-09-01

Embryonic TEA domain-containing factor (ETF) belongs to the family of proteins structurally related to transcriptional enhancer factor-1 (TEF-1) and is implicated in neural development. Isolation and characterization of the cosmid clones encoding the mouse ETF gene (Etdf) revealed that Etdf spans approximately 17.9 kb and consists of 12 exons. The exon-intron structure of Etdf closely resembles that of the Drosophila scalloped gene, indicating that these genes may have evolved from a common ancestor. Then multiple transcription initiation sites revealed by S1 protection and primer extension analyses are consistent with the absence of the canonical TATA and CAAT boxes in themore » 5{prime}-flanking region, which contains many potential regulatory sequences, such as the E-box, N-box, Sp1 element, GATA-1 element, TAATGARAT element, and B2 short interspersed element (SINE) as well as several direct and inverted repeat sequences. The Etdf locus was assigned to the proximal region of mouse chromosome 7 using fluorescence in situ hybridization and linkage mapping analyses. These results provide the molecular basis for studying the regulation, in vivo function, and evolution of Etdf. 29 refs., 5 figs., 1 tab.« less

Structural organization and chromosomal assignment of the mouse embryonic TEA domain-containing factor (ETF) gene.

PubMed

Suzuki, K; Yasunami, M; Matsuda, Y; Maeda, T; Kobayashi, H; Terasaki, H; Ohkubo, H

1996-09-01

Embryonic TEA domain-containing factor (ETF) belongs to the family of proteins structurally related to transcriptional enhancer factor-1 (TEF-1) and is implicated in neural development. Isolation and characterization of the cosmid clones encoding the mouse ETF gene (Etdf) revealed that Etdf spans approximately 17.9 kb and consists of 12 exons. The exon-intron structure of Etdf closely resembles that of the Drosophila scalloped gene, indicating that these genes may have evolved from a common ancestor. The multiple transcription initiation sites revealed by S1 protection and primer extension analyses are consistent with the absence of the canonical TATA and CAAT boxes in the 5'-flanking region, which contains many potential regulatory sequences, such as the E-box, N-box, Sp1 element, GATA-1 element, TAATGARAT element, and B2 short interspersed element (SINE) as well as several direct and inverted repeat sequences. The Etdf locus was assigned to the proximal region of mouse chromosome 7 using fluorescence in situ hybridization and linkage mapping analyses. These results provide the molecular basis for studying the regulation, in vivo function, and evolution of Etdf.

4-N-pyridin-2-yl-benzamide nanotubes compatible with mouse stem cell and oral delivery in Drosophila

NASA Astrophysics Data System (ADS)

Yadav, Jhillu S.; Lavanya, Madugula P.; Das, Pragna P.; Bag, Indira; Krishnan, Anita; Jagannadh, Bulusu; Mohapatra, Debendra K.; Pal Bhadra, Manika; Bhadra, Utpal

2010-04-01

p-aminobenzoic acid (PABA), a structural moiety of many commercial drugs, is self-assembled with linker alkyl side chains to form tubular nanostructures. The tubes exhibited fluorescence either intrinsic or from fluorescent molecules embedded in the wall during self-assembly. Uptake and inter-cellular delivery of the conjugated nanotubes in human cancer cells and in mouse embryonic stem cells were demonstrated by fluorescence imaging and flow cytometry. Biocompatibility, cytotoxicity and clearance were monitored both ex vivo in mouse multipotent embryonic stem cells and in vivo in adult Drosophila. Accumulation of nanotubes had no adverse effects and abnormalities on stem cell morphology and proliferation rate. A distinct distribution of two separate nanotubes in various internal organs of Drosophila interprets that accumulation of nanomaterials might be interdependent on the side chain modifications and physiological settings of cell or tissue types. Unlike carbon nanomaterials, exposure of PABA nanotubes does not produce any hazards including locomotion defects and mortality of adult flies. Despite differential uptake and clearance from multiple live tissues, the use of self-assembled nanotubes can add new dimensions and scope to the development of dual-purpose oral carriers for the fulfilment of many biological promises.

The maintenance of pluripotency following laser direct-write of mouse embryonic stem cells.

PubMed

Raof, Nurazhani Abdul; Schiele, Nathan R; Xie, Yubing; Chrisey, Douglas B; Corr, David T

2011-03-01

The ability to precisely pattern embryonic stem (ES) cells in vitro into predefined arrays/geometries may allow for the recreation of a stem cell niche for better understanding of how cellular microenvironmental factors govern stem cell maintenance and differentiation. In this study, a new gelatin-based laser direct-write (LDW) technique was utilized to deposit mouse ES cells into defined arrays of spots, while maintaining stem cell pluripotency. Results obtained from these studies showed that ES cells were successfully printed into specific patterns and remained viable. Furthermore, ES cells retained the expression of Oct4 in nuclei after LDW, indicating that the laser energy did not affect their maintenance of an undifferentiated state. The differentiation potential of mouse ES cells after LDW was confirmed by their ability to form embryoid bodies (EBs) and to spontaneously become cell lineages representing all three germ layers, revealed by the expression of marker proteins of nestin (ectoderm), Myf-5 (mesoderm) and PDX-1 (endoderm), after 7 days of cultivation. Gelatin-based LDW provides a new avenue for stem cell patterning, with precision and control of the cellular microenvironment. Copyright © 2010 Elsevier Ltd. All rights reserved.

RIC8A is essential for the organisation of actin cytoskeleton and cell-matrix interaction.

PubMed

Ruisu, Katrin; Meier, Riho; Kask, Keiu; Tõnissoo, Tambet; Velling, Teet; Pooga, Margus

2017-08-15

RIC8A functions as a chaperone and guanine nucleotide exchange factor for a subset of G protein α subunits. Multiple G protein subunits mediate various signalling events that regulate cell adhesion and migration and the involvement of RIC8A in some of these processes has been demonstrated. We have previously shown that the deficiency of RIC8A causes a failure in mouse gastrulation and neurogenesis - major events in embryogenesis that rely on proper association of cells with the extracellular matrix (ECM) and involve active cell migration. To elaborate on these findings, we used Ric8a -/- mouse embryonic stem cells and Ric8a-deficient mouse embryonic fibroblasts, and found that RIC8A plays an important role in the organisation and remodelling of actin cytoskeleton and cell-ECM association. Ric8a-deficient cells were able to attach to different ECM components, but were unable to spread correctly, and did not form stress fibres or focal adhesion complexes. We also found that the presence of RIC8A is necessary for the activation of β1 integrins and integrin-mediated cell migration. Copyright © 2017 Elsevier Inc. All rights reserved.

Production of medakafish chimeras from a stable embryonic stem cell line.

PubMed

Hong, Y; Winkler, C; Schartl, M

1998-03-31

Embryonic stem (ES) cell lines provide a unique tool for introducing targeted or random genetic alterations through gene replacement, insertional mutagenesis, and gene addition because they offer the possibility for in vitro selection for the desired, but extremely rare, recombinant genotypes. So far only mouse blastocyst embryos are known to have the competence to give rise to such ES cell lines. We recently have established a stable cell line (Mes1) from blastulae of the medakafish (Oryzias latipes) that shows all characteristics of mouse ES cells in vitro. Here, we demonstrate that Mes1 cells also have the competence for chimera formation; 90% of host blastulae transplanted with Mes1 cells developed into chimeric fry. This high frequency was not compromised by cryostorage or DNA transfection of the donor cells. The Mes1 cells contributed to numerous organs derived from all three germ layers and differentiated into various types of functional cells, most readily observable in pigmented chimeras. These features suggest the possibility that Mes1 cells may be a fish equivalent of mouse ES cells and that medaka can be used as another system for the application of the ES cell technology.

Production of medakafish chimeras from a stable embryonic stem cell line

PubMed Central

Hong, Yunhan; Winkler, Christoph; Schartl, Manfred

1998-01-01

Embryonic stem (ES) cell lines provide a unique tool for introducing targeted or random genetic alterations through gene replacement, insertional mutagenesis, and gene addition because they offer the possibility for in vitro selection for the desired, but extremely rare, recombinant genotypes. So far only mouse blastocyst embryos are known to have the competence to give rise to such ES cell lines. We recently have established a stable cell line (Mes1) from blastulae of the medakafish (Oryzias latipes) that shows all characteristics of mouse ES cells in vitro. Here, we demonstrate that Mes1 cells also have the competence for chimera formation; 90% of host blastulae transplanted with Mes1 cells developed into chimeric fry. This high frequency was not compromised by cryostorage or DNA transfection of the donor cells. The Mes1 cells contributed to numerous organs derived from all three germ layers and differentiated into various types of functional cells, most readily observable in pigmented chimeras. These features suggest the possibility that Mes1 cells may be a fish equivalent of mouse ES cells and that medaka can be used as another system for the application of the ES cell technology. PMID:9520425

Rap1 GTPase is required for mouse lens epithelial maintenance and morphogenesis

PubMed Central

Maddala, Rupalatha; Nagendran, Tharkika; Lang, Richard A.; Morozov, Alexei; Rao, Ponugoti V.

2015-01-01

Rap1, a Ras-like small GTPase, plays a crucial role in cell-matrix adhesive interactions, cell-cell junction formation, cell polarity and migration. The role of Rap1 in vertebrate organ development and tissue architecture, however, remains elusive. We addressed this question in a mouse lens model system using a conditional gene targeting approach. While individual germline deficiency of either Rap1a or Rap1b did not cause overt defects in mouse lens, conditional double deficiency (Rap1 cKO) prior to lens placode formation led to an ocular phenotype including microphthalmia and lens opacification in embryonic mice. The embryonic Rap1 cKO mouse lens exhibited striking defects including loss of E-cadherin- and ZO-1-based cell-cell junctions, disruption of paxillin and β1-integrin-based cell adhesive interactions along with abnormalities in cell shape and apical-basal polarity of epithelium. These epithelial changes were accompanied by increased levels of α-smooth muscle actin, vimentin and N-cadherin, and expression of transcriptional suppressors of E-cadherin (Snai1, Slug and Zeb2), and a mesenchymal metabolic protein (Dihydropyrimidine dehydrogenase). Additionally, while lens differentiation was not overtly affected, increased apoptosis and dysregulated cell cycle progression were noted in epithelium and fibers in Rap1 cKO mice. Collectively these observations uncover a requirement for Rap1 in maintenance of lens epithelial phenotype and morphogenesis. PMID:26212757

Symmetry breaking, germ layer specification and axial organisation in aggregates of mouse embryonic stem cells

PubMed Central

van den Brink, Susanne C.; Baillie-Johnson, Peter; Balayo, Tina; Hadjantonakis, Anna-Katerina; Nowotschin, Sonja; Turner, David A.; Martinez Arias, Alfonso

2014-01-01

Mouse embryonic stem cells (mESCs) are clonal populations derived from preimplantation mouse embryos that can be propagated in vitro and, when placed into blastocysts, contribute to all tissues of the embryo and integrate into the normal morphogenetic processes, i.e. they are pluripotent. However, although they can be steered to differentiate in vitro into all cell types of the organism, they cannot organise themselves into structures that resemble embryos. When aggregated into embryoid bodies they develop disorganised masses of different cell types with little spatial coherence. An exception to this rule is the emergence of retinas and anterior cortex-like structures under minimal culture conditions. These structures emerge from the cultures without any axial organisation. Here, we report that small aggregates of mESCs, of about 300 cells, self-organise into polarised structures that exhibit collective behaviours reminiscent of those that cells exhibit in early mouse embryos, including symmetry breaking, axial organisation, germ layer specification and cell behaviour, as well as axis elongation. The responses are signal specific and uncouple processes that in the embryo are tightly associated, such as specification of the anteroposterior axis and anterior neural development, or endoderm specification and axial elongation. We discuss the meaning and implications of these observations and the potential uses of these structures which, because of their behaviour, we suggest to call ‘gastruloids’. PMID:25371360

Development of an in vitro culture method for stepwise differentiation of mouse embryonic stem cells and induced pluripotent stem cells into mature osteoclasts.

PubMed

Nishikawa, Keizo; Iwamoto, Yoriko; Ishii, Masaru

2014-05-01

The development of methods for differentiation of embryonic stem cells (ESCs) and induced pluripotent stem cell (iPSCs) into functional cells have helped to analyze the mechanism regulating cellular processes and to explore cell-based assays for drug discovery. Although several reports have demonstrated methods for differentiation of mouse ESCs into osteoclast-like cells, it remains unclear whether these methods are applicable for differentiation of iPSCs to osteoclasts. In this study, we developed a simple method for stepwise differentiation of mouse ESCs and iPSCs into bone-resorbing osteoclasts based upon a monoculture approach consisting of three steps. First, based on conventional hanging-drop methods, embryoid bodies (EBs) were produced from mouse ESCs or iPSCs. Second, EBs were cultured in medium supplemented with macrophage colony-stimulating factor (M-CSF), and differentiated to osteoclast precursors, which expressed CD11b. Finally, ESC- or iPSC-derived osteoclast precursors stimulated with receptor activator of nuclear factor-B ligand (RANKL) and M-CSF formed large multinucleated osteoclast-like cells that expressed tartrate-resistant acid phosphatase and were capable of bone resorption. Molecular analysis showed that the expression of osteoclast marker genes such as Nfatc1, Ctsk, and Acp5 are increased in a RANKL-dependent manner. Thus, our procedure is simple and easy and would be helpful for stem cell-based bone research.

An efficient method for generation of bi-allelic null mutant mouse embryonic stem cells and its application for investigating epigenetic modifiers.

PubMed

Fisher, Cynthia L; Marks, Hendrik; Cho, Lily Ting-Yin; Andrews, Robert; Wormald, Sam; Carroll, Thomas; Iyer, Vivek; Tate, Peri; Rosen, Barry; Stunnenberg, Hendrik G; Fisher, Amanda G; Skarnes, William C

2017-12-01

Mouse embryonic stem (ES) cells are a popular model system to study biological processes, though uncovering recessive phenotypes requires inactivating both alleles. Building upon resources from the International Knockout Mouse Consortium (IKMC), we developed a targeting vector for second allele inactivation in conditional-ready IKMC 'knockout-first' ES cell lines. We applied our technology to several epigenetic regulators, recovering bi-allelic targeted clones with a high efficiency of 60% and used Flp recombinase to restore expression in two null cell lines to demonstrate how our system confirms causality through mutant phenotype reversion. We designed our strategy to select against re-targeting the 'knockout-first' allele and identify essential genes in ES cells, including the histone methyltransferase Setdb1. For confirmation, we exploited the flexibility of our system, enabling tamoxifen inducible conditional gene ablation while controlling for genetic background and tamoxifen effects. Setdb1 ablated ES cells exhibit severe growth inhibition, which is not rescued by exogenous Nanog expression or culturing in naive pluripotency '2i' media, suggesting that the self-renewal defect is mediated through pluripotency network independent pathways. Our strategy to generate null mutant mouse ES cells is applicable to thousands of genes and repurposes existing IKMC Intermediate Vectors. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Symmetry breaking, germ layer specification and axial organisation in aggregates of mouse embryonic stem cells.

PubMed

van den Brink, Susanne C; Baillie-Johnson, Peter; Balayo, Tina; Hadjantonakis, Anna-Katerina; Nowotschin, Sonja; Turner, David A; Martinez Arias, Alfonso

2014-11-01

Mouse embryonic stem cells (mESCs) are clonal populations derived from preimplantation mouse embryos that can be propagated in vitro and, when placed into blastocysts, contribute to all tissues of the embryo and integrate into the normal morphogenetic processes, i.e. they are pluripotent. However, although they can be steered to differentiate in vitro into all cell types of the organism, they cannot organise themselves into structures that resemble embryos. When aggregated into embryoid bodies they develop disorganised masses of different cell types with little spatial coherence. An exception to this rule is the emergence of retinas and anterior cortex-like structures under minimal culture conditions. These structures emerge from the cultures without any axial organisation. Here, we report that small aggregates of mESCs, of about 300 cells, self-organise into polarised structures that exhibit collective behaviours reminiscent of those that cells exhibit in early mouse embryos, including symmetry breaking, axial organisation, germ layer specification and cell behaviour, as well as axis elongation. The responses are signal specific and uncouple processes that in the embryo are tightly associated, such as specification of the anteroposterior axis and anterior neural development, or endoderm specification and axial elongation. We discuss the meaning and implications of these observations and the potential uses of these structures which, because of their behaviour, we suggest to call 'gastruloids'. © 2014. Published by The Company of Biologists Ltd.

An essential role for UTX in resolution and activation of bivalent promoters

PubMed Central

Dhar, Shilpa S.; Lee, Sung-Hun; Chen, Kaifu; Zhu, Guangjing; Oh, WonKyung; Allton, Kendra; Gafni, Ohad; Kim, Young Zoon; Tomoiga, Alin S.; Barton, Michelle Craig; Hanna, Jacob H.; Wang, Zhibin; Li, Wei; Lee, Min Gyu

2016-01-01

Trimethylated histone H3 lysine 27 (H3K27me3) is linked to gene silencing, whereas H3K4me3 is associated with gene activation. These two marks frequently co-occupy gene promoters, forming bivalent domains. Bivalency signifies repressed but activatable states of gene expression and can be resolved to active, H3K4me3-prevalent states during multiple cellular processes, including differentiation, development and epithelial mesenchymal transition. However, the molecular mechanism underlying bivalency resolution remains largely unknown. Here, we show that the H3K27 demethylase UTX (also called KDM6A) is required for the resolution and activation of numerous retinoic acid (RA)-inducible bivalent genes during the RA-driven differentiation of mouse embryonic stem cells (ESCs). Notably, UTX loss in mouse ESCs inhibited the RA-driven bivalency resolution and activation of most developmentally critical homeobox (Hox) a–d genes. The UTX-mediated resolution and activation of many bivalent Hox genes during mouse ESC differentiation were recapitulated during RA-driven differentiation of human NT2/D1 embryonal carcinoma cells. In support of the importance of UTX in bivalency resolution, Utx-null mouse ESCs and UTX-depleted NT2/D1 cells displayed defects in RA-driven cellular differentiation. Our results define UTX as a bivalency-resolving histone modifier necessary for stem cell differentiation. PMID:26762983

Engineering human cell spheroids to model embryonic tissue fusion in vitro.

EPA Science Inventory

Epithelial-mesenchymal interactions drive embryonic fusion events during development and upon perturbation can result in birth defects. Cleft palate and neural tube defects can result from genetic defects or environmental exposures during development, yet very little is known abo...

Gelatin-Derived Graphene–Silicate Hybrid Materials Are Biocompatible and Synergistically Promote BMP9-Induced Osteogenic Differentiation of Mesenchymal Stem Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou, Yulong; Qazvini, Nader Taheri; Zane, Kylie

Graphene-based materials are used in many fields but have found only limited applications in biomedicine, including bone tissue engineering. Here, we demonstrate that novel hybrid materials consisting of gelatin-derived graphene and silicate nanosheets of Laponite (GL) are biocompatible and promote osteogenic differentiation of mesenchymal stem cells (MSCs). Homogeneous cell attachment, long-term proliferation, and osteogenic differentiation of MSCs on a GL-scaffold were confirmed using optical microscopy and scanning electron microscopy. GL-powders made by pulverizing the GL-scaffold were shown to promote bone morphogenetic protein (BMP9)-induced osteogenic differentiation. GL-powders increased the alkaline phosphatase (ALP) activity in immortalized mouse embryonic fibroblasts but decreased themore » ALP activity in more-differentiated immortalized mouse adipose-derived cells. Note, however, that GL-powders promoted BMP9-induced calcium mineral deposits in both MSC lines, as assessed using qualitative and quantitative alizarin red assays. Furthermore, the expression of chondro-osteogenic regulator markers such as Runx2, Sox9, osteopontin, and osteocalcin was upregulated by the GL-powder, independent of BMP9 stimulation; although the powder synergistically upregulated the BMP9-induced Osterix expression, the adipogenic marker PPAR gamma was unaffected. Furthermore, in vivo stem cell implantation experiments demonstrated that GL-powder could significantly enhance the BMP9-induced ectopic bone formation from MSCs. Collectively, our results strongly suggest that the GL hybrid materials promote BMP9-induced osteogenic differentiation of MSCs and hold promise for the development of bone tissue engineering platforms.« less

Signaling hierarchy regulating human endothelial cell development

USDA-ARS?s Scientific Manuscript database

Our present knowledge of the regulation of mammalian endothelial cell differentiation has been largely derived from studies of mouse embryonic development. However, unique mechanisms and hierarchy of signals that govern human endothelial cell development are unknown and, thus, explored in these stud...

Dynamic gene expression of Lin-28 during embryonic development in mouse and chicken.

PubMed

Yokoyama, Shigetoshi; Hashimoto, Megumi; Shimizu, Hirohito; Ueno-Kudoh, Hiroe; Uchibe, Kenta; Kimura, Ichiro; Asahara, Hiroshi

2008-02-01

The Caenorhabditis elegans heterochronic gene lin-28 regulates developmental timing in the nematode trunk. We report the dynamic expression patterns of Lin-28 homologues in mouse and chick embryos. Whole mount in situ hybridization revealed specific and intriguing expression patterns of Lin-28 in the developing mouse and chick limb bud. Mouse Lin-28 expression was detected in both the forelimb and hindlimb at E9.5, but disappeared from the forelimb at E10.5, and finally from the forelimb and hindlimb at E11.5. Chicken Lin-28, which was first detected in the limb primordium at stage 15/16, was also downregulated as the stage proceeded. The amino acid sequences of mouse and chicken Lin-28 genes are highly conserved and the similar expression patterns of Lin-28 during limb development in mouse and chicken suggest that this heterochronic gene is also conserved during vertebrate limb development.

Highly variable penetrance of abnormal phenotypes in embryonic lethal knockout mice

PubMed Central

Wilson, Robert; Geyer, Stefan H.; Reissig, Lukas; Rose, Julia; Szumska, Dorota; Hardman, Emily; Prin, Fabrice; McGuire, Christina; Ramirez-Solis, Ramiro; White, Jacqui; Galli, Antonella; Tudor, Catherine; Tuck, Elizabeth; Mazzeo, Cecilia Icoresi; Smith, James C.; Robertson, Elizabeth; Adams, David J.; Mohun, Timothy; Weninger, Wolfgang J.

2017-01-01

Background: Identifying genes that are essential for mouse embryonic development and survival through term is a powerful and unbiased way to discover possible genetic determinants of human developmental disorders. Characterising the changes in mouse embryos that result from ablation of lethal genes is a necessary first step towards uncovering their role in normal embryonic development and establishing any correlates amongst human congenital abnormalities. Methods: Here we present results gathered to date in the Deciphering the Mechanisms of Developmental Disorders (DMDD) programme, cataloguing the morphological defects identified from comprehensive imaging of 220 homozygous mutant and 114 wild type embryos from 42 lethal and subviable lines, analysed at E14.5. Results: Virtually all mutant embryos show multiple abnormal phenotypes and amongst the 42 lines these affect most organ systems. Within each mutant line, the phenotypes of individual embryos form distinct but overlapping sets. Subcutaneous edema, malformations of the heart or great vessels, abnormalities in forebrain morphology and the musculature of the eyes are all prevalent phenotypes, as is loss or abnormal size of the hypoglossal nerve. Conclusions: Overall, the most striking finding is that no matter how profound the malformation, each phenotype shows highly variable penetrance within a mutant line. These findings have challenging implications for efforts to identify human disease correlates. PMID:27996060

Multivariate Calibration Approach for Quantitative Determination of Cell-Line Cross Contamination by Intact Cell Mass Spectrometry and Artificial Neural Networks.

PubMed

Valletta, Elisa; Kučera, Lukáš; Prokeš, Lubomír; Amato, Filippo; Pivetta, Tiziana; Hampl, Aleš; Havel, Josef; Vaňhara, Petr

2016-01-01

Cross-contamination of eukaryotic cell lines used in biomedical research represents a highly relevant problem. Analysis of repetitive DNA sequences, such as Short Tandem Repeats (STR), or Simple Sequence Repeats (SSR), is a widely accepted, simple, and commercially available technique to authenticate cell lines. However, it provides only qualitative information that depends on the extent of reference databases for interpretation. In this work, we developed and validated a rapid and routinely applicable method for evaluation of cell culture cross-contamination levels based on mass spectrometric fingerprints of intact mammalian cells coupled with artificial neural networks (ANNs). We used human embryonic stem cells (hESCs) contaminated by either mouse embryonic stem cells (mESCs) or mouse embryonic fibroblasts (MEFs) as a model. We determined the contamination level using a mass spectra database of known calibration mixtures that served as training input for an ANN. The ANN was then capable of correct quantification of the level of contamination of hESCs by mESCs or MEFs. We demonstrate that MS analysis, when linked to proper mathematical instruments, is a tangible tool for unraveling and quantifying heterogeneity in cell cultures. The analysis is applicable in routine scenarios for cell authentication and/or cell phenotyping in general.

Multivariate Calibration Approach for Quantitative Determination of Cell-Line Cross Contamination by Intact Cell Mass Spectrometry and Artificial Neural Networks

PubMed Central

Prokeš, Lubomír; Amato, Filippo; Pivetta, Tiziana; Hampl, Aleš; Havel, Josef; Vaňhara, Petr

2016-01-01

Cross-contamination of eukaryotic cell lines used in biomedical research represents a highly relevant problem. Analysis of repetitive DNA sequences, such as Short Tandem Repeats (STR), or Simple Sequence Repeats (SSR), is a widely accepted, simple, and commercially available technique to authenticate cell lines. However, it provides only qualitative information that depends on the extent of reference databases for interpretation. In this work, we developed and validated a rapid and routinely applicable method for evaluation of cell culture cross-contamination levels based on mass spectrometric fingerprints of intact mammalian cells coupled with artificial neural networks (ANNs). We used human embryonic stem cells (hESCs) contaminated by either mouse embryonic stem cells (mESCs) or mouse embryonic fibroblasts (MEFs) as a model. We determined the contamination level using a mass spectra database of known calibration mixtures that served as training input for an ANN. The ANN was then capable of correct quantification of the level of contamination of hESCs by mESCs or MEFs. We demonstrate that MS analysis, when linked to proper mathematical instruments, is a tangible tool for unraveling and quantifying heterogeneity in cell cultures. The analysis is applicable in routine scenarios for cell authentication and/or cell phenotyping in general. PMID:26821236

Mouse hypospadias: A critical examination and definition.

PubMed

Sinclair, Adriane Watkins; Cao, Mei; Shen, Joel; Cooke, Paul; Risbridger, Gail; Baskin, Laurence; Cunha, Gerald R

2016-12-01

Hypospadias is a common malformation whose etiology is based upon perturbation of normal penile development. The mouse has been previously used as a model of hypospadias, despite an unacceptably wide range of definitions for this malformation. The current paper presents objective criteria and a definition of mouse hypospadias. Accordingly, diethylstilbestrol (DES) induced penile malformations were examined at 60 days postnatal (P60) in mice treated with DES over the age range of 12 days embryonic to 20 days postnatal (E12-P20). DES-induced hypospadias involves malformation of the urethral meatus, which is most severe in DES E12-P10, DES P0-P10 and DES P5-P15 groups, and less so or absent in the other treatment groups. A frenulum-like ventral tether between the penis and the prepuce was seen in the most severely affected DES-treated mice. Internal penile morphology was also altered in the DES E12-P10, DES P0-P10 and DES P5-P15 groups (with little effect in the other DES treatment groups). Thus, adverse effects of DES are a function of the period of DES treatment and most severe in the P0-P10 period. In "estrogen mutant mice" (NERKI, βERKO, αERKO and AROM+) hypospadias was only seen in AROM+ male mice having genetically-engineered elevation is serum estrogen. Significantly, mouse hypospadias was only seen distally at and near the urethral meatus where epithelial fusion events are known to take place and never in the penile midshaft, where urethral formation occurs via an entirely different morphogenetic process. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Genetically engineered mouse models for functional studies of SKP1-CUL1-F-box-protein (SCF) E3 ubiquitin ligases.

PubMed

Zhou, Weihua; Wei, Wenyi; Sun, Yi

2013-05-01

The SCF (SKP1 (S-phase-kinase-associated protein 1), Cullin-1, F-box protein) E3 ubiquitin ligases, the founding member of Cullin-RING ligases (CRLs), are the largest family of E3 ubiquitin ligases in mammals. Each individual SCF E3 ligase consists of one adaptor protein SKP1, one scaffold protein cullin-1 (the first family member of the eight cullins), one F-box protein out of 69 family members, and one out of two RING (Really Interesting New Gene) family proteins RBX1/ROC1 or RBX2/ROC2/SAG/RNF7. Various combinations of these four components construct a large number of SCF E3s that promote the degradation of many key regulatory proteins in cell-context, temporally, and spatially dependent manners, thus controlling precisely numerous important cellular processes, including cell cycle progression, apoptosis, gene transcription, signal transduction, DNA replication, maintenance of genome integrity, and tumorigenesis. To understand how the SCF E3 ligases regulate these cellular processes and embryonic development under in vivo physiological conditions, a number of mouse models with transgenic (Tg) expression or targeted deletion of components of SCF have been established and characterized. In this review, we will provide a brief introduction to the ubiquitin-proteasome system (UPS) and the SCF E3 ubiquitin ligases, followed by a comprehensive overview on the existing Tg and knockout (KO) mouse models of the SCF E3s, and discuss the role of each component in mouse embryogenesis, cell proliferation, apoptosis, carcinogenesis, as well as other pathogenic processes associated with human diseases. We will end with a brief discussion on the future directions of this research area and the potential applications of the knowledge gained to more effective therapeutic interventions of human diseases.

Advances in understanding paternally transmitted Chromosomal Abnormalities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marchetti, F; Sloter, E; Wyrobek, A J

2001-03-01

Multicolor FISH has been adapted for detecting the major types of chromosomal abnormalities in human sperm including aneuploidies for clinically-relevant chromosomes, chromosomal aberrations including breaks and rearrangements, and other numerical abnormalities. The various sperm FISH assays have been used to evaluate healthy men, men of advanced age, and men who have received mutagenic cancer therapy. The mouse has also been used as a model to investigate the mechanism of paternally transmitted genetic damage. Sperm FISH for the mouse has been used to detect chromosomally abnormal mouse sperm, while the PAINT/DAPI analysis of mouse zygotes has been used to evaluate themore » types of chromosomal defects that can be paternally transmitted to the embryo and their effects on embryonic development.« less

The chromosomal mapping of four genes encoding winged helix proteins expressed early in mouse development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Labosky, P.A.; Sakaki, Hiroshi; Hogan, B.L.M.

1996-06-01

Members of the winged helix family of transcription factors are required for the normal embryonic development of the mouse. Using the interspecific backcross panel from The Jackson Laboratory, we have determined the chromosomal locations of four genes that encode winged helix containing proteins. Mf1 was assigned to mouse Chromosome 8, Mf2 to Chromosome 4, Mf3 to Chromosome 9, and Mf4 to Chromosome 13. Since Mf3 is located in a region of Chromosome 9 containing many well-characterized mouse mutations such as short ear (se), ashen (ash), and dilute (d), we have analyzed deletion mutants to determine the location of Mf3 moremore » precisely. 14 refs., 3 figs.« less

Targeted Disruption of Mouse Yin Yang 1 Transcription Factor Results in Peri-Implantation Lethality

PubMed Central

Donohoe, Mary E.; Zhang, Xiaolin; McGinnis, Lynda; Biggers, John; Li, En; Shi, Yang

1999-01-01

Yin Yang 1 (YY1) is a zinc finger-containing transcription factor and a target of viral oncoproteins. To determine the biological role of YY1 in mammalian development, we generated mice deficient for YY1 by gene targeting. Homozygosity for the mutated YY1 allele results in embryonic lethality in the mouse. YY1 mutants undergo implantation and induce uterine decidualization but rapidly degenerate around the time of implantation. A subset of YY1 heterozygote embryos are developmentally retarded and exhibit neurulation defects, suggesting that YY1 may have additional roles during later stages of mouse embryogenesis. Our studies demonstrate an essential function for YY1 in the development of the mouse embryo. PMID:10490658

Directed differentiation of embryonic stem cells using a bead-based combinatorial screening method.

PubMed

Tarunina, Marina; Hernandez, Diana; Johnson, Christopher J; Rybtsov, Stanislav; Ramathas, Vidya; Jeyakumar, Mylvaganam; Watson, Thomas; Hook, Lilian; Medvinsky, Alexander; Mason, Chris; Choo, Yen

2014-01-01

We have developed a rapid, bead-based combinatorial screening method to determine optimal combinations of variables that direct stem cell differentiation to produce known or novel cell types having pre-determined characteristics. Here we describe three experiments comprising stepwise exposure of mouse or human embryonic cells to 10,000 combinations of serum-free differentiation media, through which we discovered multiple novel, efficient and robust protocols to generate a number of specific hematopoietic and neural lineages. We further demonstrate that the technology can be used to optimize existing protocols in order to substitute costly growth factors with bioactive small molecules and/or increase cell yield, and to identify in vitro conditions for the production of rare developmental intermediates such as an embryonic lymphoid progenitor cell that has not previously been reported.

Regulatory RNA Key Player in p53-Mediated Apoptosis in Embryonic Stem Cells | Center for Cancer Research

Cancer.gov

Embryonic stem cells (ESCs) must maintain the integrity of their genomes or risk passing potentially deleterious mutations on to numerous tissues. Thus, ESCs have a unique genome surveillance system and easily undergo apoptosis or differentiation when DNA damage is detected. The protein p53 is known to promote differentiation in mouse ESCs (mESCs), but its role in DNA damage-induced apoptosis (DIA) is unclear. p53 may have a pro-apoptotic function since it can regulate apoptotic genes in embryonal cells. Given that ESCs have a distinct transcriptional program, Jing Huang, Ph.D., of CCR’s Laboratory of Cancer Biology and Genetics, and his colleagues wondered whether p53 might regulate DIA in ESCs by utilizing the ESC-specific expression program.

Organogenesis of heart-vascular system derived from mouse 2 cell stage embryos and from early embryonic stem cells in vitro.

PubMed

Ishiwata, Isamu; Tamagawa, Tomoharu; Tokieda, Yuko; Iguchi, Megumi; Sato, Kahei; Ishikawa, Hiroshi

2003-03-01

Regenerative medical treatment with embryonic stem cells (an ES cell) is a goal for organ transplantation. Structures that are tubular in nature (i.e. blood capillaries) were induced from early embryonic stem (EES) cells in vitro using embryotrophic factor (ETFs). In addition, cardiac muscle cells could be identified as well. However, differentiation of EES cells into a complete cardiovascular system was difficult because 3 germ layer primordial organs are directed embryologically in various ways and it is not possible to guide only cardiovascular organs. Thus, we introduced ETFs after the formation of an embryoid body and were successful in cloning cell clusters that beat, thus deriving only cardiovascular organs. The application of this to the treatment of various cardiovascular diseases is promising.

Regulation of the Mouse Treacher Collins Syndrome Homolog (Tcof1) Promoter Through Differential Repression of Constitutive Expression

PubMed Central

Shiang, Rita

2008-01-01

Treacher Collins syndrome is an autosomal-dominant mandibulofacial dysostosis caused by haploinsufficiency of the TCOF1 gene product treacle. Mouse Tcof1 protein is approximately 61% identical and 71% similar to treacle, and heterozygous knockout of Tcof1 causes craniofacial malformation. Tcof1 expression is high in developing neural crest, but much lower in other tissues. To investigate this dual regulation, highly conserved regions upstream of TCOF1 homologs were tested through deletion and mutation reporter assays, and conserved predicted transcription factor binding sites were assessed through chromatin binding studies. Assays were performed in mouse P19 embryonic carcinoma cells and in HEK293 cells to determine differential activation in cell types at different stages of differentiation. Binding of Cebpb, Zfp161, and Sp1 transcription factors was specific to the Tcof1 regulatory region in P19 cells. The Zfp161 binding site demonstrated P19 cell–specific repression, while the Sp1/Sp3 candidate site demonstrated HEK293 cell–specific activation. Moreover, presence of c-myb and Zfp161 transcripts was specific to P19 cells. A minimal promoter fragment from −253 to +43 bp directs constitutive expression in both cell types, and dual regulation of Tcof1 appears to be through differential repression of this minimal promoter. The CpG island at the transcription start site remains unmethylated in P19 cells, 11.5 dpc mouse embryonic tissue, and adult mouse ear, which supports constitutive activation of the Tcof1 promoter. PMID:18771418

Comprehensive Identification of Krüppel-Like Factor Family Members Contributing to the Self-Renewal of Mouse Embryonic Stem Cells and Cellular Reprogramming.

PubMed

Jeon, Hyojung; Waku, Tsuyoshi; Azami, Takuya; Khoa, Le Tran Phuc; Yanagisawa, Jun; Takahashi, Satoru; Ema, Masatsugu

2016-01-01

Pluripotency is maintained in mouse embryonic stem (ES) cells and is induced from somatic cells by the activation of appropriate transcriptional regulatory networks. Krüppel-like factor gene family members, such as Klf2, Klf4 and Klf5, have important roles in maintaining the undifferentiated state of mouse ES cells as well as in cellular reprogramming, yet it is not known whether other Klf family members exert self-renewal and reprogramming functions when overexpressed. In this study, we examined whether overexpression of any representative Klf family member, such as Klf1-Klf10, would be sufficient for the self-renewal of mouse ES cells. We found that only Klf2, Klf4, and Klf5 produced leukemia inhibitory factor (LIF)-independent self-renewal, although most KLF proteins, if not all, have the ability to occupy the regulatory regions of Nanog, a critical Klf target gene. We also examined whether overexpression of any of Klf1-Klf10 would be sufficient to convert epiblast stem cells into a naïve pluripotent state and found that Klf5 had such reprogramming ability, in addition to Klf2 and Klf4. We also delineated the functional domains of the Klf2 protein for LIF-independent self-renewal and reprogramming. Interestingly, we found that both the N-terminal transcriptional activation and C-terminal zinc finger domains were indispensable for this activity. Taken together, our comprehensive analysis provides new insight into the contribution of Klf family members to mouse ES self-renewal and cellular reprogramming.

Comparison of Toxicity of Benzene Metabolite Hydroquinone in Hematopoietic Stem Cells Derived from Murine Embryonic Yolk Sac and Adult Bone Marrow

PubMed Central

Zhu, Jie; Wang, Hong; Yang, Shuo; Guo, Liqiao; Li, Zhen; Wang, Wei; Wang, Suhan; Huang, Wenting; Wang, Liping; Yang, Tan; Ma, Qiang; Bi, Yongyi

2013-01-01

Benzene is an occupational toxicant and an environmental pollutant that potentially causes hematotoxicity and leukemia in exposed populations. Epidemiological studies suggest an association between an increased incidence of childhood leukemia and benzene exposure during the early stages of pregnancy. However, experimental evidence supporting the association is lacking at the present time. It is believed that benzene and its metabolites target hematopoietic stem cells (HSCs) to cause toxicity and cancer in the hematopoietic system. In the current study, we compared the effects of hydroquinone (HQ), a major metabolite of benzene in humans and animals, on mouse embryonic yolk sac hematopoietic stem cells (YS-HSCs) and adult bone marrow hematopoietic stem cells (BM-HSCs). YS-HSCs and BM-HSCs were isolated and enriched, and were exposed to HQ at increasing concentrations. HQ reduced the proliferation and the differentiation and colony formation, but increased the apoptosis of both YS-HSCs and BM-HSCs. However, the cytotoxic and apoptotic effects of HQ were more apparent and reduction of colony formation by HQ was more severe in YS-HSCs than in BM-HSCs. Differences in gene expression profiles were observed in HQ-treated YS-HSCs and BM-HSCs. Cyp4f18 was induced by HQ both in YS-HSCs and BM-HSCs, whereas DNA-PKcs was induced in BM-HSCs only. The results revealed differential effects of benzene metabolites on embryonic and adult HSCs. The study established an experimental system for comparison of the hematopoietic toxicity and leukemogenicity of benzene and metabolites during mouse embryonic development and adulthood. PMID:23940708

Cubilin, a high affinity receptor for fibroblast growth factor 8, is required for cell survival in the developing vertebrate head.

PubMed

Cases, Olivier; Perea-Gomez, Aitana; Aguiar, Diego P; Nykjaer, Anders; Amsellem, Sabine; Chandellier, Jacqueline; Umbhauer, Muriel; Cereghini, Silvia; Madsen, Mette; Collignon, Jérôme; Verroust, Pierre; Riou, Jean-François; Creuzet, Sophie E; Kozyraki, Renata

2013-06-07

Cubilin (Cubn) is a multiligand endocytic receptor critical for the intestinal absorption of vitamin B12 and renal protein reabsorption. During mouse development, Cubn is expressed in both embryonic and extra-embryonic tissues, and Cubn gene inactivation results in early embryo lethality most likely due to the impairment of the function of extra-embryonic Cubn. Here, we focus on the developmental role of Cubn expressed in the embryonic head. We report that Cubn is a novel, interspecies-conserved Fgf receptor. Epiblast-specific inactivation of Cubn in the mouse embryo as well as Cubn silencing in the anterior head of frog or the cephalic neural crest of chick embryos show that Cubn is required during early somite stages to convey survival signals in the developing vertebrate head. Surface plasmon resonance analysis reveals that fibroblast growth factor 8 (Fgf8), a key mediator of cell survival, migration, proliferation, and patterning in the developing head, is a high affinity ligand for Cubn. Cell uptake studies show that binding to Cubn is necessary for the phosphorylation of the Fgf signaling mediators MAPK and Smad1. Although Cubn may not form stable ternary complexes with Fgf receptors (FgfRs), it acts together with and/or is necessary for optimal FgfR activity. We propose that plasma membrane binding of Fgf8, and most likely of the Fgf8 family members Fgf17 and Fgf18, to Cubn improves Fgf ligand endocytosis and availability to FgfRs, thus modulating Fgf signaling activity.

Identification of Pro-Differentiation p53 Target Genes and Evaluation of Expression in Normal and Malignant Mammary Gland

DTIC Science & Technology

2008-04-01

genes such as c -myc and Klf-4, frequently upregulated in tumors also have been shown to establish and preserve the ES cell phenotype and the rapid...proliferation of ES cells in culture. More importantly, the introduction of these four factors (Oct3/4, Sox-2, c -myc and Klf-4) into mouse embryonic or...GTA-3’; mouse nanog: sense 5’-AAG TAC CTC AGC CTC CAG CA-3’, antisense 5’-CGT AAG GCT GCA GAA AGT GC-3’; mouse c -myc: sense 5’-CAC CAT GCC CCT CAA CGT

A potential inhibitory function of draxin in regulating mouse trunk neural crest migration.

PubMed

Zhang, Sanbing; Su, Yuhong; Gao, Jinbao; Zhang, Chenbing; Tanaka, Hideaki

2017-01-01

Draxin is a repulsive axon guidance protein that plays important roles in the formation of three commissures in the central nervous system and dorsal interneuron 3 (dI3) in the chick spinal cord. In the present study, we report the expression pattern of mouse draxin in the embryonic mouse trunk spinal cord. In the presence of draxin, the longest net migration length of a migrating mouse trunk neural crest cell was significantly reduced. In addition, the relative number of apolar neural crest cells increased as the draxin treatment time increased. Draxin caused actin cytoskeleton rearrangement in the migrating trunk neural crest cells. Our data suggest that draxin may regulate mouse trunk neural crest cell migration by the rearrangement of cell actin cytoskeleton and by reducing the polarization activity of these cells subsequently.

Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) Assay: Book Chapter

EPA Science Inventory

There are thousands of environmental chemicals for which there is limited toxicological information, motivating the development and application of in vitro systems to profile the biological effects of xenobiotic exposure and predict their potential developmental hazard. An adher...

Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay-Book Chapter*

EPA Science Inventory

There are thousands of environmental chemicals for which there is limited toxicological information, motivating the development and application of in vitro systems to profile the biological effects of xenobiotic exposure and predict their potential developmental hazard. An adhere...

Evaluating the Genetic, Hormonal, and Exogenous Factors Affecting Somatic Copy Number Variation in Breast Cancer

DTIC Science & Technology

2016-10-01

progress in subaim 1a, substantially improving the design of our proposed transgenic animal, the “deletion reporter mouse”, and are finalizing cloning...of necessary components. We expect to submit embryonic stem cells to the transgenic facility within the next few months. Furthermore, subaim 1b is...different mammary epithelial subpopulations. We will breed the reporter mouse created in aim 1 (or the CAG/UBC-GFP mouse) with BRCA1+/- and ATM+/- mutant

Droplet Microarray Based on Patterned Superhydrophobic Surfaces Prevents Stem Cell Differentiation and Enables High-Throughput Stem Cell Screening.

PubMed

Tronser, Tina; Popova, Anna A; Jaggy, Mona; Bastmeyer, Martin; Levkin, Pavel A

2017-12-01

Over the past decades, stem cells have attracted growing interest in fundamental biological and biomedical research as well as in regenerative medicine, due to their unique ability to self-renew and differentiate into various cell types. Long-term maintenance of the self-renewal ability and inhibition of spontaneous differentiation, however, still remain challenging and are not fully understood. Uncontrolled spontaneous differentiation of stem cells makes high-throughput screening of stem cells also difficult. This further hinders investigation of the underlying mechanisms of stem cell differentiation and the factors that might affect it. In this work, a dual functionality of nanoporous superhydrophobic-hydrophilic micropatterns is demonstrated in their ability to inhibit differentiation of mouse embryonic stem cells (mESCs) and at the same time enable formation of arrays of microdroplets (droplet microarray) via the effect of discontinuous dewetting. Such combination makes high-throughput screening of undifferentiated mouse embryonic stem cells possible. The droplet microarray is used to investigate the development, differentiation, and maintenance of stemness of mESC, revealing the dependence of stem cell behavior on droplet volume in nano- and microliter scale. The inhibition of spontaneous differentiation of mESCs cultured on the droplet microarray for up to 72 h is observed. In addition, up to fourfold increased cell growth rate of mESCs cultured on our platform has been observed. The difference in the behavior of mESCs is attributed to the porosity and roughness of the polymer surface. This work demonstrates that the droplet microarray possesses the potential for the screening of mESCs under conditions of prolonged inhibition of stem cells' spontaneous differentiation. Such a platform can be useful for applications in the field of stem cell research, pharmacological testing of drug efficacy and toxicity, biomedical research as well as in the field of regenerative medicine and tissue engineering. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Growth and differentiation of embryonic stem cells that lack an intact c-fos gene.

PubMed Central

Field, S J; Johnson, R S; Mortensen, R M; Papaioannou, V E; Spiegelman, B M; Greenberg, M E

1992-01-01

The c-fos protooncogene encodes a transcription factor that is thought to play a critical role in proliferation and differentiation as well as in the physiological response of mature cells to their environment. To test directly the role of c-fos in growth and differentiation, we generated mouse embryonic stem cell lines in which both copies of the c-fos gene were specifically disrupted by homologous recombination. Remarkably, the disruption of both copies of c-fos in these cells has no detectable effect on embryonic stem cell viability, growth rate, or differentiation potential. Embryonic stem cells lacking c-fos can differentiate into a wide range of cell types in tissue culture and also in chimeric mice. We conclude that despite a large body of literature suggesting an important role for c-fos in cell growth and differentiation, in at least some cell types this gene is not essential for these processes. Images PMID:1329091

A structure-based extracellular matrix expansion mechanism of fibrous tissue growth

PubMed Central

Kalson, Nicholas S; Lu, Yinhui; Taylor, Susan H; Starborg, Tobias; Holmes, David F; Kadler, Karl E

2015-01-01

Embryonic growth occurs predominately by an increase in cell number; little is known about growth mechanisms later in development when fibrous tissues account for the bulk of adult vertebrate mass. We present a model for fibrous tissue growth based on 3D-electron microscopy of mouse tendon. We show that the number of collagen fibrils increases during embryonic development and then remains constant during postnatal growth. Embryonic growth was explained predominately by increases in fibril number and length. Postnatal growth arose predominately from increases in fibril length and diameter. A helical crimp structure was established in embryogenesis, and persisted postnatally. The data support a model where the shape and size of tendon is determined by the number and position of embryonic fibroblasts. The collagen fibrils that these cells synthesise provide a template for postnatal growth by structure-based matrix expansion. The model has important implications for growth of other fibrous tissues and fibrosis. DOI: http://dx.doi.org/10.7554/eLife.05958.001 PMID:25992598

[Recent contributions to the establishment of the axes of the mammalian embryo].

PubMed

Catala, M

2002-06-01

The study of the establishment of embryonic axes during early development has shown that this process is a very early event (occurRing either during ovogenesis or during fertilization) for invertebrates and for lower vertebrates. In mammals, it was considered that this establishment appears late during development because of the great plasticity of blastomeres. Recent data in the mouse embryon show that the mammalian ovocyte is a polarized cell, the polar body corresponding to the animal pole of this cell. The blastomeres that are generated by the zygote divide asynchronously. The first that divides is the one which inherits the plasma cell membrane where fertilization takes place. This blastomere will preferentially give rise to the cells of the embryonic pole of the blastocyst whereas the other yields the cells of the abembryonic pole. The mammalian ovocyte is thus a polarized cell with an already established animal-vegetal axis. The point of sperm entry will determine the embryonic-abembryonic axis.

Targeted disruption of a novel gene contiguous to both glucocerebrodisidase (GC) and thrombospondin 3 (TSP3), results in an embryonic lethal phenotype in the mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bornstein, P.; Shingu, T.; LaMarca, M.E.

1994-09-01

We have identified a new murine gene, termed gene X, that spans the 6 kb interval separating GC from TSP3. Mutations in GC result in Gaucher disease, the most common lysosomal storage disorder. Gene X and GC are transcribed convergently; their major polyadenylation sites are separated by only 431 bp. On the other hand, gene X and TSP3 are transcribed divergently and share a bidirectional promoter. The cDNA for gene X encodes a 317 amino acid protein, without either a signal sequence or N-linked glycosylation. Gene X is expressed ubiquitously in tissues of the young adult mouse, but no closemore » homologues have been found in the DNA or protein data bases. A targeted point mutation was introduced into the GC gene (Asn to Ser in exon 9) by homologous recombination in embryonic stem cells to establish a mouse model for a mild form of Gaucher disease. In the process, a PGK-neomycin gene cassette was inserted in the 3{prime} flanking region of GC as a selectable marker, in a sequence that was subsequently identified as exon 8 of gene X. Mice homozygous for the combined mutation die early in gestation. Since the amino acid mutation in humans is associated with milder type 1 Gaucher disease, we conclude that gene X is essential for embryonic development in mice. The locations of human and murine GC, gene X and TSP3 are similar, but the human genome includes a duplication that has produced GC and gene X pseudogenes. We are currently studying the possible functional interactions of GC, gene X and TSP3 in both mice and humans.« less

Transforming growth factor-β signalling controls human breast cancer metastasis in a zebrafish xenograft model.

PubMed

Drabsch, Yvette; He, Shuning; Zhang, Long; Snaar-Jagalska, B Ewa; ten Dijke, Peter

2013-11-07

The transforming growth factor beta (TGF-β) signalling pathway is known to control human breast cancer invasion and metastasis. We demonstrate that the zebrafish xenograft assay is a robust and dependable animal model for examining the role of pharmacological modulators and genetic perturbation of TGF-β signalling in human breast tumour cells. We injected cancer cells into the embryonic circulation (duct of cuvier) and examined their invasion and metastasis into the avascular collagenous tail. Various aspects of the TGF-β signalling pathway were blocked by chemical inhibition, small interfering RNA (siRNA), or small hairpin RNA (shRNA). Analysis was conducted using fluorescent microscopy. Breast cancer cells with different levels of malignancy, according to in vitro and in vivo mouse studies, demonstrated invasive and metastatic properties within the embryonic zebrafish model that nicely correlated with their differential tumourigenicity in mouse models. Interestingly, MCF10A M2 and M4 cells invaded into the caudal hematopoietic tissue and were visible as a cluster of cells, whereas MDA MB 231 cells invaded into the tail fin and were visible as individual cells. Pharmacological inhibition with TGF-β receptor kinase inhibitors or tumour specific Smad4 knockdown disturbed invasion and metastasis in the zebrafish xenograft model and closely mimicked the results we obtained with these cells in a mouse metastasis model. Inhibition of matrix metallo proteinases, which are induced by TGF-β in breast cancer cells, blocked invasion and metastasis of breast cancer cells. The zebrafish-embryonic breast cancer xenograft model is applicable for the mechanistic understanding, screening and development of anti-TGF-β drugs for the treatment of metastatic breast cancer in a timely and cost-effective manner.

A reliable and economical method for gaining mouse embryonic fibroblasts capable of preparing feeder layers.

PubMed

Jiang, Guangming; Wan, Xiaoju; Wang, Ming; Zhou, Jianhua; Pan, Jian; Wang, Baolong

2016-08-01

Mouse embryonic fibroblasts (MEFs) are widely used to prepare feeder layers for culturing embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) in vitro. Transportation lesions and exorbitant prices make the commercially obtained MEFs unsuitable for long term research. The aim of present study is to establish a method, which enables researchers to gain MEFs from mice and establish feeder layers by themselves in ordinary laboratories. MEFs were isolated from ICR mouse embryos at 12.5-17.5 day post-coitum (DPC) and cultured in vitro. At P2-P7, the cells were inactivated with mitomycin C or by X-ray irradiation. Then they were used to prepare feeder layers. The key factors of the whole protocol were analyzed to determine the optimal conditions for the method. The results revealed MEFs isolated at 12.5-13.5 DPC, and cultured to P3 were the best choice for feeder preparation, those P2 and P4-P5 MEFs were also suitable for the purpose. The P3-P5 MEFs treated with 10 μg/ml of mitomycin C for 3 h, or irradiated with X-ray at 1.5 Gy/min for 25 Gy were the most suitable feeder cells. Treating MEFs with 10 μg/ml of mitomycin C for 2.5 h, 15 μg/ml for 2.0 h, or irradiating the cells with 20 Gy of X-ray at 2.0 Gy/min could all serve as alternative methods for P3-P4 cells. Our study provides a reliable and economical way to obtain large amount of qualified MEFs for long term research of ESCs or iPSCs.

Cyclic mechanical strain maintains Nanog expression through PI3K/Akt signaling in mouse embryonic stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horiuchi, Rie; Akimoto, Takayuki, E-mail: akimoto@m.u-tokyo.ac.jp; Institute for Biomedical Engineering, Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 513 Waseda-tsurumaki, Shinjuku, Tokyo 162-0041

2012-08-15

Mechanical strain has been reported to affect the proliferation/differentiation of many cell types; however, the effects of mechanotransduction on self-renewal as well as pluripotency of embryonic stem (ES) cells remains unknown. To investigate the effects of mechanical strain on mouse ES cell fate, we examined the expression of Nanog, which is an essential regulator of self-renewal and pluripotency as well as Nanog-associated intracellular signaling during uniaxial cyclic mechanical strain. The mouse ES cell line, CCE was plated onto elastic membranes, and we applied 10% strain at 0.17 Hz. The expression of Nanog was reduced during ES cell differentiation in responsemore » to the withdrawal of leukemia inhibitory factor (LIF); however, two days of cyclic mechanical strain attenuated this reduction of Nanog expression. On the other hand, the cyclic mechanical strain promoted PI3K-Akt signaling, which is reported as an upstream of Nanog transcription. The cyclic mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor wortmannin. Furthermore, cytochalasin D, an inhibitor of actin polymerization, also inhibited the mechanical strain-induced increase in phospho-Akt. These findings imply that mechanical force plays a role in regulating Nanog expression in ES cells through the actin cytoskeleton-PI3K-Akt signaling. -- Highlights: Black-Right-Pointing-Pointer The expression of Nanog, which is an essential regulator of 'stemness' was reduced during embryonic stem (ES) cell differentiation. Black-Right-Pointing-Pointer Cyclic mechanical strain attenuated the reduction of Nanog expression. Black-Right-Pointing-Pointer Cyclic mechanical strain promoted PI3K-Akt signaling and mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor and an inhibitor of actin polymerization.« less

Ultrasound-guided microinjection into the mouse forebrain in utero at E9.5.

PubMed

Pierfelice, Tarran J; Gaiano, Nicholas

2010-11-13

In utero survival surgery in mice permits the molecular manipulation of gene expression during development. However, because the uterine wall is opaque during early embryogenesis, the ability to target specific parts of the embryo for microinjection is greatly limited. Fortunately, high-frequency ultrasound imaging permits the generation of images that can be used in real time to guide a microinjection needle into the embryonic region of interest. Here we describe the use of such imaging to guide the injection of retroviral vectors into the ventricular system of the mouse forebrain at embryonic day (E) 9.5. This method uses a laparotomy to permit access to the uterine horns, and a specially designed plate that permits host embryos to be bathed in saline while they are imaged and injected. Successful surgeries often result in most or all of the injected embryos surviving to any subsequent time point of interest (embryonically or postnatally). The principles described here can be used with slight modifications to perform injections into the amnionic fluid of E8.5 embryos (thereby permitting infection along the anterior posterior extent of the neural tube, which has not yet closed), or into the ventricular system of the brain at E10.5/11.5. Furthermore, at mid-neurogenic ages (~E13.5), ultrasound imaging can be used direct injection into specific brain regions for viral infection or cell transplantation. The use of ultrasound imaging to guide in utero injections in mice is a very powerful technique that permits the molecular and cellular manipulation of mouse embryos in ways that would otherwise be exceptionally difficult if not impossible.

Embryonic germ cells from mice and rats exhibit properties consistent with a generic pluripotent ground state

PubMed Central

Leitch, Harry G.; Blair, Kate; Mansfield, William; Ayetey, Harold; Humphreys, Peter; Nichols, Jennifer; Surani, M. Azim; Smith, Austin

2010-01-01

Mouse and rat embryonic stem cells can be sustained in defined medium by dual inhibition (2i) of the mitogen-activated protein kinase (Erk1/2) cascade and of glycogen synthase kinase 3. The inhibitors suppress differentiation and enable self-renewal of pluripotent cells that are ex vivo counterparts of naïve epiblast cells in the mature blastocyst. Pluripotent stem cell lines can also be derived from unipotent primordial germ cells via a poorly understood process of epigenetic reprogramming. These are termed embryonic germ (EG) cells to denote their distinct origin. Here we investigate whether EG cell self-renewal and derivation are supported by 2i. We report that mouse EG cells can be established with high efficiency using 2i in combination with the cytokine leukaemia inhibitory factor (LIF). Furthermore, addition of fibroblast growth factor or stem cell factor is unnecessary using 2i-LIF. The derived EG cells contribute extensively to healthy chimaeric mice, including to the germline. Using the same conditions, we describe the first derivations of EG cells from the rat. Rat EG cells express a similar marker profile to rat and mouse ES cells. They have a diploid karyotype, can be clonally expanded and genetically manipulated, and are competent for multilineage colonisation of chimaeras. These findings lend support to the postulate of a conserved molecular ground state in pluripotent rodent cells. Future research will determine the extent to which this is maintained in other mammals and whether, in some species, primordial germ cells might be a more tractable source than epiblast for the capture of naïve pluripotent stem cells. PMID:20519324

Loss of Mitofusin 2 Promotes Endoplasmic Reticulum Stress*

PubMed Central

Ngoh, Gladys A.; Papanicolaou, Kyriakos N.; Walsh, Kenneth

2012-01-01

The outer mitochondrial membrane GTPase mitofusin 2 (Mfn2) is known to regulate endoplasmic reticulum (ER) shape in addition to its mitochondrial fusion effects. However, its role in ER stress is unknown. We report here that induction of ER stress with either thapsigargin or tunicamycin in mouse embryonic fibroblasts leads to up-regulation of Mfn2 mRNA and protein levels with no change in the expression of the mitochondrial shaping factors Mfn1, Opa1, Drp1, and Fis1. Genetic deletion of Mfn2 but not Mfn1 in mouse embryonic fibroblasts or cardiac myocytes in mice led to an increase in the expression of the ER chaperone proteins. Genetic ablation of Mfn2 in mouse embryonic fibroblasts amplified ER stress and exacerbated ER stress-induced apoptosis. Deletion of Mfn2 delayed translational recovery through prolonged eIF2α phosphorylation associated with decreased GADD34 and p58IPK expression and elevated C/EBP homologous protein induction at late time points. These changes in the unfolded protein response were coupled to increased cell death reflected by augmented caspase 3/7 activity, lactate dehydrogenase release from cells, and an increase in propidium iodide-positive nuclei in response to thapsigargin or tunicamycin treatment. In contrast, genetic deletion of Mfn1 did not affect ER stress-mediated increase in ER chaperone synthesis or eIF2α phosphorylation. Additionally, ER stress-induced C/EBP homologous protein, GADD34, and p58IPK induction and cell death were not affected by loss of Mfn1. We conclude that Mfn2 but not Mfn1 is an ER stress-inducible protein that is required for the proper temporal sequence of the ER stress response. PMID:22511781

Reduced Collagen Deposition in Infarcted Myocardium Facilitates Induced Pluripotent Stem Cell Engraftment and Angiomyogenesis for Improvement of Left Ventricular Function

PubMed Central

Dai, Bo; Huang, Wei; Xu, Meifeng; Millard, Ronald W.; Gao, Mei Hua; Hammond, H. Kirk; Menick, Donald R.; Ashraf, Muhammad; Wang, Yigang

2012-01-01

Objectives The purpose of this study was to assess the effect of scar tissue composition on engraftment of progenitor cells into infarcted myocardium. Background Scar tissue formation after myocardial infarction creates a barrier that severely compromises tissue regeneration, limiting potential functional recovery. Methods In vitro: A tricell patch (Tri-P) was created from peritoneum seeded and cultured with induced pluripotent stem cell–derived cardiomyocytes, endothelial cells, and mouse embryonic fibroblasts. The expression of fibrosis-related molecules from mouse embryonic fibroblasts and infarcted heart was measured by Western blot and quantitative reverse transcriptase polymerase chain reaction. In vivo: A Tri-P was affixed over the entire infarcted area 7 days after myocardial infarction in mice overexpressing adenylyl cyclase 6 (AC6). Engraftment efficiency of progenitor cells in hearts of AC6 mice was compared with that of control wild-type (WT) mice using a combination of in vivo bioluminescence imaging, post-mortem ex vivo tissue analysis, and the number of green fluorescent protein–positive cells. Echocardiography of left ventricular (LV) function was performed weekly. Hearts were harvested for analysis 4 weeks after Tri-P application. Mouse embryonic fibroblasts were stimulated with forskolin before an anoxia/reoxygenation protocol. Fibrosis-related molecules were analyzed. Results In AC6 mice, infarcted hearts treated with Tri-P showed significantly higher bioluminescence imaging intensity and numbers of green fluorescent protein–positive cells than in WT mice. LV function improved progressively in AC6 mice from weeks 2 to 4 and was associated with reduced LV fibrosis. Conclusions Application of a Tri-P in AC6 mice resulted in significantly higher induced pluripotent stem cell engraftment accompanied by angiomyogenesis in the infarcted area and improvement in LV function. PMID:22051336

[Influence of extremely low-frequency magnetic field on circadian rhythm of cryptochrome in mouse embryonic fibroblasts].

PubMed

Sun, Z Y; Geng, D Y; Chen, C F; Wang, P P; Song, T

2017-06-20

Objective: To investigate the influence of extremely low-frequency magnetic field on periodical expression of cryptochrome ( Cry ) gene in mouse embryonic fibroblast NIH3T3 cells. Methods: The NIH3T3 cells were divided into magnetic field group and sham-exposure group. The NIH3T3 cells in the magnetic field group were stimulated by horse serum and then exposed to an extremely low-frequency magnetic field (50 Hz and 0.3 mT) for 48 hours, and those in the sham-exposure group were also stimulated by horse serum and then exposed to a coil for 48 hours. The NIH3T3 cells were collected, total RNA was extracted, and cDNA was obtained via reverse transcription. Real-time fluorescent quantitative RT-PCR was used to measure the changes in transcription cycles of Cry and Period genes in both groups. Results: There was no significant difference in the proliferation rate at 0, 12, 24, and 48 hours of exposure between the two groups ( P >0.05) . Both sham-exposure group and magnetic field group showed a rhythmic change in the expression of Cry gene, and compared with the sham-exposure group, the magnetic field group had a significantly shortened circadian rhythm of Cry gene in NIH3T3 cells ( t =2.57, P <0.05) . Both groups had rhythmic and periodical expression of Period gene and there was no significant difference between the two groups ( t =0.70, P >0.05) . Conclusion: Extremely low-frequency magnetic field can significantly shorten the circadian rhythm of Cry gene in mouse embryonic fibroblasts, while there is no significant change in the circadian rhythm of Period gene.

Protein arginine methyltransferase 7-mediated microRNA-221 repression maintains Oct4, Nanog, and Sox2 levels in mouse embryonic stem cells.

PubMed

Chen, Tsai-Yu; Lee, Sung-Hun; Dhar, Shilpa S; Lee, Min Gyu

2018-03-16

The stemness maintenance of embryonic stem cells (ESCs) requires pluripotency transcription factors, including Oct4, Nanog, and Sox2. We have previously reported that protein arginine methyltransferase 7 (PRMT7), an epigenetic modifier, is an essential pluripotency factor that maintains the stemness of mouse ESCs, at least in part, by down-regulating the expression of the anti-stemness microRNA (miRNA) miR-24-2. To gain greater insight into the molecular basis underlying PRMT7-mediated maintenance of mouse ESC stemness, we searched for new PRMT7-down-regulated anti-stemness miRNAs. Here, we show that miR-221 gene-encoded miR-221-3p and miR-221-5p are anti-stemness miRNAs whose expression levels in mouse ESCs are directly repressed by PRMT7. Notably, both miR-221-3p and miR-221-5p targeted the 3' untranslated regions of mRNA transcripts of the major pluripotency factors Oct4, Nanog, and Sox2 to antagonize mouse ESC stemness. Moreover, miR-221-5p silenced also the expression of its own transcriptional repressor PRMT7. Transfection of miR-221-3p and miR-221-5p mimics induced spontaneous differentiation of mouse ESCs. CRISPR-mediated deletion of the miR-221 gene, as well as specific antisense inhibitors of miR-221-3p and miR-221-5p, inhibited the spontaneous differentiation of PRMT7-depleted mouse ESCs. Taken together, these findings reveal that the PRMT7-mediated repression of miR-221-3p and miR-221-5p expression plays a critical role in maintaining mouse ESC stemness. Our results also establish miR-221-3p and miR-221-5p as anti-stemness miRNAs that target Oct4 , Nanog , and Sox2 mRNAs in mouse ESCs. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Mouse Cytotoxic T Cell-derived Granzyme B Activates the Mitochondrial Cell Death Pathway in a Bim-dependent Fashion*

PubMed Central

Catalán, Elena; Jaime-Sánchez, Paula; Aguiló, Nacho; Simon, Markus M.; Froelich, Christopher J.; Pardo, Julián

2015-01-01

Cytotoxic T cells (Tc) use perforin and granzyme B (gzmB) to kill virus-infected cells and cancer cells. Recent evidence suggests that human gzmB primarily induces apoptosis via the intrinsic mitochondrial pathway by either cleaving Bid or activating Bim leading to the activation of Bak/Bax and subsequent generation of active caspase-3. In contrast, mouse gzmB is thought to predominantly induce apoptosis by directly processing pro-caspase-3. However, in certain mouse cell types gzmB-mediated apoptosis mainly occurs via the mitochondrial pathway. To investigate whether Bim is involved under the latter conditions, we have now employed ex vivo virus-immune mouse Tc that selectively kill by using perforin and gzmB (gzmB+Tc) as effector cells and wild type as well as Bim- or Bak/Bax-deficient spontaneously (3T9) or virus-(SV40) transformed mouse embryonic fibroblast cells as targets. We show that gzmB+Tc-mediated apoptosis (phosphatidylserine translocation, mitochondrial depolarization, cytochrome c release, and caspase-3 activation) was severely reduced in 3T9 cells lacking either Bim or both Bak and Bax. This outcome was related to the ability of Tc cells to induce the degradation of Mcl-1 and Bcl-XL, the anti-apoptotic counterparts of Bim. In contrast, gzmB+Tc-mediated apoptosis was not affected in SV40-transformed mouse embryonic fibroblast cells lacking Bak/Bax. The data provide evidence that Bim participates in mouse gzmB+Tc-mediated apoptosis of certain targets by activating the mitochondrial pathway and suggest that the mode of cell death depends on the target cell. Our results suggest that the various molecular events leading to transformation and/or immortalization of cells have an impact on their relative resistance to the multiple gzmB+Tc-induced death pathways. PMID:25605735

Spatial stochastic modelling of the Hes1 gene regulatory network: intrinsic noise can explain heterogeneity in embryonic stem cell differentiation.

PubMed

Sturrock, Marc; Hellander, Andreas; Matzavinos, Anastasios; Chaplain, Mark A J

2013-03-06

Individual mouse embryonic stem cells have been found to exhibit highly variable differentiation responses under the same environmental conditions. The noisy cyclic expression of Hes1 and its downstream genes are known to be responsible for this, but the mechanism underlying this variability in expression is not well understood. In this paper, we show that the observed experimental data and diverse differentiation responses can be explained by a spatial stochastic model of the Hes1 gene regulatory network. We also propose experiments to control the precise differentiation response using drug treatment.

Dynamic Imaging of Mouse Embryos and Cardiodynamics in Static Culture.

PubMed

Lopez, Andrew L; Larina, Irina V

2018-01-01

The heart is a dynamic organ that quickly undergoes morphological and mechanical changes through early embryonic development. Characterizing these early moments is important for our understanding of proper embryonic development and the treatment of heart disease. Traditionally, tomographic imaging modalities and fluorescence-based microscopy are excellent approaches to visualize structural features and gene expression patterns, respectively, and connect aberrant gene programs to pathological phenotypes. However, these approaches usually require static samples or fluorescent markers, which can limit how much information we can derive from the dynamic and mechanical changes that regulate heart development. Optical coherence tomography (OCT) is unique in this circumstance because it allows for the acquisition of three-dimensional structural and four-dimensional (3D + time) functional images of living mouse embryos without fixation or contrast reagents. In this chapter, we focus on how OCT can visualize heart morphology at different stages of development and provide cardiodynamic information to reveal mechanical properties of the developing heart.

Transient Downregulation of Nanog and Oct4 Induced by DETA/NO Exposure in Mouse Embryonic Stem Cells Leads to Mesodermal/Endodermal Lineage Differentiation

PubMed Central

Mora-Castilla, Sergio; Tejedo, Juan R.; Díaz, Irene; Hitos, Ana B.; Cahuana, Gladys M.; Hmadcha, Abdelkrim; Martín, Franz; Soria, Bernat

2014-01-01

The function of pluripotency genes in differentiation is a matter of investigation. We report here that Nanog and Oct4 are reexpressed in two mouse embryonic stem cell (mESC) lines following exposure to the differentiating agent DETA/NO. Both cell lines express a battery of both endoderm and mesoderm markers following induction of differentiation with DETA/NO-based protocols. Confocal analysis of cells undergoing directed differentiation shows that the majority of cells expressing Nanog express also endoderm genes such as Gata4 and FoxA2 (75.4% and 96.2%, resp.). Simultaneously, mRNA of mesodermal markers Flk1 and Mef2c are also regulated by the treatment. Acetylated histone H3 occupancy at the promoter of Nanog is involved in the process of reexpression. Furthermore, Nanog binding to the promoter of Brachyury leads to repression of this gene, thus disrupting mesendoderm transition. PMID:25544848

In Vitro Derivation and Propagation of Spermatogonial Stem Cell Activity from Mouse Pluripotent Stem Cells.

PubMed

Ishikura, Yukiko; Yabuta, Yukihiro; Ohta, Hiroshi; Hayashi, Katsuhiko; Nakamura, Tomonori; Okamoto, Ikuhiro; Yamamoto, Takuya; Kurimoto, Kazuki; Shirane, Kenjiro; Sasaki, Hiroyuki; Saitou, Mitinori

2016-12-06

The in vitro derivation and propagation of spermatogonial stem cells (SSCs) from pluripotent stem cells (PSCs) is a key goal in reproductive science. We show here that when aggregated with embryonic testicular somatic cells (reconstituted testes), primordial germ cell-like cells (PGCLCs) induced from mouse embryonic stem cells differentiate into spermatogonia-like cells in vitro and are expandable as cells that resemble germline stem cells (GSCs), a primary cell line with SSC activity. Remarkably, GSC-like cells (GSCLCs), but not PGCLCs, colonize adult testes and, albeit less effectively than GSCs, contribute to spermatogenesis and fertile offspring. Whole-genome analyses reveal that GSCLCs exhibit aberrant methylation at vulnerable regulatory elements, including those critical for spermatogenesis, which may restrain their spermatogenic potential. Our study establishes a strategy for the in vitro derivation of SSC activity from PSCs, which, we propose, relies on faithful epigenomic regulation. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Deciphering the mechanisms of developmental disorders: phenotype analysis of embryos from mutant mouse lines

PubMed Central

Wilson, Robert; McGuire, Christina; Mohun, Timothy

2016-01-01

The Deciphering the Mechanisms of Developmental Disorders (DMDD) consortium is a research programme set up to identify genes in the mouse, which if mutated (or knocked-out) result in embryonic lethality when homozygous, and initiate the study of why disruption of their function has such profound effects on embryo development and survival. The project uses a combination of comprehensive high resolution 3D imaging and tissue histology to identify abnormalities in embryo and placental structures of embryonic lethal lines. The image data we have collected and the phenotypes scored are freely available through the project website (http://dmdd.org.uk). In this article we describe the web interface to the images that allows the embryo data to be viewed at full resolution in different planes, discuss how to search the database for a phenotype, and our approach to organising the data for an embryo and a mutant line so it is easy to comprehend and intuitive to navigate. PMID:26519470

The death-inducer obliterator 1 (Dido1) gene regulates embryonic stem cell self-renewal.

PubMed

Liu, Yinyin; Kim, Hyeung; Liang, Jiancong; Lu, Weisi; Ouyang, Bin; Liu, Dan; Songyang, Zhou

2014-02-21

The regulatory network of factors that center on master transcription factors such as Oct4, Nanog, and Sox2 help maintain embryonic stem (ES) cells and ensure their pluripotency. The target genes of these master transcription factors define the ES cell transcriptional landscape. In this study, we report our findings that Dido1, a target of canonical transcription factors such as Oct4, Sox2, and Nanog, plays an important role in regulating ES cell maintenance. We found that depletion of Dido1 in mouse ES cells led to differentiation, and ectopic expression of Dido1 inhibited differentiation induced by leukemia inhibitory factor withdrawal. We further demonstrated that whereas Nanog and Oct4 could occupy the Dido1 locus and promote its transcription, Dido1 could also target to the loci of pluripotency factors such as Nanog and Oct4 and positively regulate their expression. Through this feedback and feedforward loop, Dido1 is able to regulate self-renewal of mouse ES cells.

Efficient differentiation of mouse embryonic stem cells into insulin-producing cells.

PubMed

Liu, Szu-Hsiu; Lee, Lain-Tze

2012-01-01

Embryonic stem (ES) cells are a potential source of a variety of differentiated cells for cell therapy, drug discovery, and toxicology screening. Here, we present an efficacy strategy for the differentiation of mouse ES cells into insulin-producing cells (IPCs) by a two-step differentiation protocol comprising of (i) the formation of definitive endoderm in monolayer culture by activin A, and (ii) this monolayer endoderm being induced to differentiate into IPCs by nicotinamide, insulin, and laminin. Differentiated cells can be obtained within approximately 7 days. The differentiation IPCs combined application of RT-PCR, ELISA, and immunofluorescence to characterize phenotypic and functional properties. In our study, we demonstrated that IPCs produced pancreatic transcription factors, endocrine progenitor marker, definitive endoderm, pancreatic β-cell markers, and Langerhans α and δ cells. The IPCs released insulin in a manner that was dose dependent upon the amount of glucose added. These techniques may be able to be applied to human ES cells, which would have very important ramifications for treating human disease.

Pontin functions as an essential coactivator for Oct4-dependent lincRNA expression in mouse embryonic stem cells.

PubMed

Boo, Kyungjin; Bhin, Jinhyuk; Jeon, Yoon; Kim, Joomyung; Shin, Hi-Jai R; Park, Jong-Eun; Kim, Kyeongkyu; Kim, Chang Rok; Jang, Hyonchol; Kim, In-Hoo; Kim, V Narry; Hwang, Daehee; Lee, Ho; Baek, Sung Hee

2015-04-10

The actions of transcription factors, chromatin modifiers and noncoding RNAs are crucial for the programming of cell states. Although the importance of various epigenetic machineries for controlling pluripotency of embryonic stem (ES) cells has been previously studied, how chromatin modifiers cooperate with specific transcription factors still remains largely elusive. Here, we find that Pontin chromatin remodelling factor plays an essential role as a coactivator for Oct4 for maintenance of pluripotency in mouse ES cells. Genome-wide analyses reveal that Pontin and Oct4 share a substantial set of target genes involved in ES cell maintenance. Intriguingly, we find that the Oct4-dependent coactivator function of Pontin extends to the transcription of large intergenic noncoding RNAs (lincRNAs) and in particular linc1253, a lineage programme repressing lincRNA, is a Pontin-dependent Oct4 target lincRNA. Together, our findings demonstrate that the Oct4-Pontin module plays critical roles in the regulation of genes involved in ES cell fate determination.

Chemotherapy-Induced Depletion of OCT4-Positive Cancer Stem Cells in a Mouse Model of Malignant Testicular Cancer.

PubMed

Pierpont, Timothy M; Lyndaker, Amy M; Anderson, Claire M; Jin, Qiming; Moore, Elizabeth S; Roden, Jamie L; Braxton, Alicia; Bagepalli, Lina; Kataria, Nandita; Hu, Hilary Zhaoxu; Garness, Jason; Cook, Matthew S; Capel, Blanche; Schlafer, Donald H; Southard, Teresa; Weiss, Robert S

2017-11-14

Testicular germ cell tumors (TGCTs) are among the most responsive solid cancers to conventional chemotherapy. To elucidate the underlying mechanisms, we developed a mouse TGCT model featuring germ cell-specific Kras activation and Pten inactivation. The resulting mice developed malignant, metastatic TGCTs composed of teratoma and embryonal carcinoma, the latter of which exhibited stem cell characteristics, including expression of the pluripotency factor OCT4. Consistent with epidemiological data linking human testicular cancer risk to in utero exposures, embryonic germ cells were susceptible to malignant transformation, whereas adult germ cells underwent apoptosis in response to the same oncogenic events. Treatment of tumor-bearing mice with genotoxic chemotherapy not only prolonged survival and reduced tumor size but also selectively eliminated the OCT4-positive cancer stem cells. We conclude that the chemosensitivity of TGCTs derives from the sensitivity of their cancer stem cells to DNA-damaging chemotherapy. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

GATA-1 directly regulates Nanog in mouse embryonic stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wen-Zhong; Ai, Zhi-Ying; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100

2015-09-25

Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation.more » Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression. - Highlights: • The Nanog proximal promoter conceives functional element for GATA-1. • GATA-1 occupies the Nanog proximal promoter in vitro and in vivo. • GATA-1 transcriptionally suppresses Nanog.« less

Suppression of Red Blood Cell Autofluorescence for Immunocytochemistry on Fixed Embryonic Mouse Tissue.

PubMed

Whittington, Niteace C; Wray, Susan

2017-10-23

Autofluorescence is a problem that interferes with immunofluorescent staining and complicates data analysis. Throughout the mouse embryo, red blood cells naturally fluoresce across multiple wavelengths, spanning the emission and excitation spectra of many commonly used fluorescent reporters, including antibodies, dyes, stains, probes, and transgenic proteins, making it difficult to distinguish assay fluorescence from endogenous fluorescence. Several tissue treatment methods have been developed to bypass this issue with varying degrees of success. Sudan Black B dye has been commonly used to quench autofluorescence, but can also introduce background fluorescence. Here we present a protocol for an alternative called TrueBlack Lipofuscin Autofluorescence Quencher. The protocol described in this unit demonstrates how TrueBlack efficiently quenches red blood cell autofluorescence across red and green wavelengths in fixed embryonic tissue without interfering with immunofluorescent signal intensity or introducing background staining. We also identify optimal incubation, concentration, and multiple usage conditions for routine immunofluorescence microscopy. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

[Radiation situation prognosis for deep space: reactions of water and living systems to chronic low-dose ionizing irradiation].

PubMed

Ushakov, I B; Tsetlin, V V; Moisa, S S

2013-01-01

The authors review the findings of researches into the effects of low-dose ionizing irradiation on diverse biological objects (embryonic Japanese quails, Aspergillus niger, Spirostomum ambiguum Ehrbg., mesenchymal stem cells from mouse marrow, dry higher plants seeds, blood lymphocytes from pilots and cosmonauts). Model experiments with chronic exposure to ionizing radiation doses comparable with the measurements inside orbital vehicles and estimations for trips through the interplanetary space resulted in morphological disorders (embryonic Japanese quails, Aspergillus niger), radiation hormesis (Aspergillus niger, MSCs from mouse marrow), increase in the seed germination rate, inhibition of Spirostomum spontaneous activity, DNA damages, chromosomal aberrations, and increase of the blood lymphocytes reactivity to additional radiation loading. These facts give grounds to assume that the crucial factor in the radiation outcomes is changes in liquid medium. In other words, during extended orbiting within the magnetosphere region and interplanetary missions ionizing radiation affects primarily liquids of organism and, secondarily, its morphofunctional structures.

Establishing Mouse Models for Zika Virus-induced Neurological Disorders Using Intracerebral Injection Strategies: Embryonic, Neonatal, and Adult.

PubMed

Herrlinger, Stephanie A; Shao, Qiang; Ma, Li; Brindley, Melinda; Chen, Jian-Fu

2018-04-26

The Zika virus (ZIKV) is a flavivirus currently endemic in North, Central, and South America. It is now established that the ZIKV can cause microcephaly and additional brain abnormalities. However, the mechanism underlying the pathogenesis of ZIKV in the developing brain remains unclear. Intracerebral surgical methods are frequently used in neuroscience research to address questions about both normal and abnormal brain development and brain function. This protocol utilizes classical surgical techniques and describes methods that allow one to model ZIKV-associated human neurological disease in the mouse nervous system. While direct brain inoculation does not model the normal mode of virus transmission, the method allows investigators to ask targeted questions concerning the consequence after ZIKV infection of the developing brain. This protocol describes embryonic, neonatal, and adult stages of intraventricular inoculation of ZIKV. Once mastered, this method can become a straightforward and reproducible technique that only takes a few hours to perform.

A chronological expression profile of gene activity during embryonic mouse brain development.

PubMed

Goggolidou, P; Soneji, S; Powles-Glover, N; Williams, D; Sethi, S; Baban, D; Simon, M M; Ragoussis, I; Norris, D P

2013-12-01

The brain is a functionally complex organ, the patterning and development of which are key to adult health. To help elucidate the genetic networks underlying mammalian brain patterning, we conducted detailed transcriptional profiling during embryonic development of the mouse brain. A total of 2,400 genes were identified as showing differential expression between three developmental stages. Analysis of the data identified nine gene clusters to demonstrate analogous expression profiles. A significant group of novel genes of as yet undiscovered biological function were detected as being potentially relevant to brain development and function, in addition to genes that have previously identified roles in the brain. Furthermore, analysis for genes that display asymmetric expression between the left and right brain hemispheres during development revealed 35 genes as putatively asymmetric from a combined data set. Our data constitute a valuable new resource for neuroscience and neurodevelopment, exposing possible functional associations between genes, including novel loci, and encouraging their further investigation in human neurological and behavioural disorders.

Cytotoxic Effects of Dillapiole on Embryonic Development of Mouse Blastocysts in Vitro and in Vivo

PubMed Central

Chan, Wen-Hsiung

2014-01-01

We examined the cytotoxic effects of dillapiole, a phenylpropanoid with antileishmanial, anti-inflammatory, antifungal, and acaricidal activities, on the blastocyst stage of mouse embryos, subsequent embryonic attachment and outgrowth in vitro, and in vivo implantation via embryo transfer. Blastocysts treated with 2.5–10 μM dillapiole exhibited a significant increase in apoptosis and corresponding decrease in total cell number. Notably, the implantation success rates of blastocysts pretreated with dillapiole were lower than those of their control counterparts. Moreover, in vitro treatment with 2.5–10 μM dillapiole was associated with increased resorption of post-implantation embryos and decreased fetal weight. Our results collectively indicate that dillapiole induces apoptosis and retards early post-implantation development, both in vitro and in vivo. However, the extent to which this organic compound exerts teratogenic effects on early human development is not known at present. Further studies are required to establish effective protection strategies against the cytotoxic effects of dillapiole. PMID:24933639

Chemical composition of the essential oil from basil (Ocimum basilicum Linn.) and its in vitro cytotoxicity against HeLa and HEp-2 human cancer cell lines and NIH 3T3 mouse embryonic fibroblasts.

PubMed

Kathirvel, Poonkodi; Ravi, Subban

2012-01-01

This study examines the chemical composition and in vitro anticancer activity of the essential oil from Ocimum basilicum Linn. (Lamiaceae), cultivated in the Western Ghats of South India. The chemical compositions of basil fresh leaves were identified by GC-MS: 11 components were identified. The major constituents were found to be methyl cinnamate (70.1%), linalool (17.5%), β-elemene (2.6%) and camphor (1.52%). The results revealed that this plant may belong to the methyl cinnamate and linalool chemotype. A methyl thiazol tetrazolium assay was used for in vitro cytotoxicity screening against the human cervical cancer cell line (HeLa), human laryngeal epithelial carcinoma cell line (HEp-2) and NIH 3T3 mouse embryonic fibroblasts. The IC(50) values obtained were 90.5 and 96.3 µg mL(-1), respectively, and the results revealed that basil oil has potent cytotoxicity.

The let-7 microRNA target gene, Mlin41/Trim71 is required for mouse embryonic survival and neural tube closure

PubMed Central

Schulman, Betsy R. Maller; Liang, Xianping; Stahlhut, Carlos; DelConte, Casey; Stefani, Giovanni; Slack, Frank J.

2010-01-01

In the nematode Caenorhabditis elegans, the let-7 microRNA (miRNA) controls the timing of key developmental events and terminal differentiation in part by directly regulating lin-41. C. elegans lin-41 mutants display precocious cell cycle exit and terminal differentiation of epidermal skin cells. lin-41 orthologues are found in more complex organisms including both mice and humans, but their roles are not known. We generated Mlin41 mouse mutants to ascertain a functional role for Mlin41. Strong loss of function Mlin41 gene-trap mutants demonstrated a striking neural tube closure defect during development, and embryonic lethality. Like C. elegans lin-41, Mlin41 also appears to be regulated by the let-7 and mir-125 miRNAs. Since Mlin41 is required for neural tube closure and survival it points to human lin-41 (HLIN41/TRIM71) as a potential human development and disease gene. PMID:19098426

Increasing levels of estradiol are deleterious to embryonic implantation because they directly affect the embryo.

PubMed

Valbuena, D; Martin, J; de Pablo, J L; Remohí, J; Pellicer, A; Simón, C

2001-11-01

To investigate whether the deleterious effect of E(2) on embryonic implantation is due to a direct effect on the endometrium, on the embryo, or both. Prospective, controlled in vitro study. Tertiary infertility center. Fertile patients in the luteal phase with histologically normal endometrium who were attending the infertility clinic as oocyte donors (n = 14). E(2) dose-response (0, 10(-8), 10(-7), 10(-6), 10(-5), and 10(-4) M) and time course (day 2 vs. day 5) experiments were performed in an in vitro embryo adhesion assay composed of human polarized endometrial epithelial cells obtained from fertile patients and mouse embryos. Blastocyst formation rate and embryo adhesion rate. Monolayers of polarized endometrial epithelial cells expressed ERalpha at the mRNA level. The E(2) dose response of blastocysts with polarized endometrial epithelial cells (n = 235) demonstrated a progressive reduction in embryonic adhesion that was statistically significant at 10(-6) M. When polarized endometrial epithelial cells were treated alone with increasing doses of E(2) for 3 days and E(2) was then removed and blastocysts added (n = 410), embryonic adhesion was not significantly reduced, except at 10(-4) M. When 2-day mouse embryos (n = 609) were treated with increasing E(2) concentrations until day 5, the rate of blastocyst formation significantly decreased at a concentration >or= 10(-6) M, and embryonic adhesion decreased when blastocysts (n = 400) were obtained at a concentration >or= 10(-7) M. Time course experiments of embryos cultured for 2 days with polarized endometrial epithelial cells (n = 426) showed that the adhesion rate was higher at E(2) levels of 10(-7), 10(-6) and 10(-5) M compared with embryos cultured for 5 days (n = 495). High E(2) levels are deleterious to embryo adhesion in vitro, mainly because they have a direct toxic effect on the embryo that may occur at the cleavage stage.

Rat embryonic palatal shelves respond to TCDD in organ culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbott, B.D.; Birnbaum, L.S.

1990-05-01

TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), a highly toxic environmental contaminant, is teratogenic in mice, inducing cleft palate (CP) and hydronephrosis at doses which are not overtly maternally or embryo toxic. Palatal shelves of embryonic mice respond to TCDD, both in vivo and in organ culture, with altered differentiation of medial epithelial cells. By contrast, in the rat TCDD produces substantial maternal, embryonic, and fetal toxicity, including fetal lethality, with few malformations. In this study the possible effects of maternal toxicity on induction of cleft palate were eliminated by exposure of embryonic rat palatal shelves in organ culture. The shelves were examined for specificmore » TCDD-induced alterations in differentiation of the medial cells. On Gestation Day (GD) 14 or 15 palatal shelves from embryonic F344 rats were placed in organ culture for 2 to 3 days (IMEM:F12 medium, 5% FBS, 0.1% DMSO) containing 0, 1 x 10(-8), 1 x 10(-9), 1 x 10(-10), or 5 x 10(-11) M TCDD. The medial epithelial peridermal cells degenerated on shelves exposed to control media or 5 x 10(-11) M TCDD. Exposure to 10(-10), 10(-9), and 10(-8) M TCDD inhibited this degeneration in 20, 36, and 60% of the shelves, respectively, and was statistically significant at the two highest doses. A normally occurring decrease in (3H)TdR incorporation was inhibited in some GD 15 shelves cultured with 10(-10) and 10(-9) M TCDD. The medial cells of TCDD-exposed shelves continued to express high levels of immunohistochemically detected EGF receptors. The altered differentiation of rat medial epithelium is similar to that reported for TCDD-exposed mouse medial cells in vivo and in vitro. However, in order to obtain these responses, the cultured rat shelves require much higher concentrations of TCDD than the mouse shelves.« less

Effect of antioxidant of bamboo leaves on gene expression associated with mouse embryonic fibroblast reproduction and embryonic development.

PubMed

Yu, Feng; Qian, Xiaowei; Zeng, Zhanghui; Zhao, Xiaoli; Hou, Rong; Zhang, Zhihe; Bian, Hongwu; Han, Ning; Wang, Junhui; Zhu, Muyuan

2017-11-01

Antioxidant of bamboo leaves (AOB) was certified to be a natural antioxidant by the Chinese Ministry of Health in 2003. However, the effects of AOB on animal reproductive and developmental functions remain unclear. The present study aimed to investigate the effects of different concentrations of AOB on mouse embryonic fibroblast (MEF) cells, and to examine the underlying molecular mechanism through which AOB affects the proliferation and apoptosis of MEFs. MEFs prepared from individual embryos were treated with various dosages of AOB. Cell viability and apoptosis were detected by MTT and flow cytometry assays, respectively. Reverse transcription‑quantitative polymerase chain reaction and western blot analyses were used for the detection of mRNA and protein expression. Functional annotation of differentially‑expressed genes was performed according to the Gene Ontology database and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Compared with the control group, ~50% of MEF cells were inhibited following treatment with a 400 µg/ml concentration of AOB. Treatment with 400 µg/ml AOB for 72 h significantly increased the apoptotic rate of MEF cells compared with the control group. Following treatment with AOB, dehydrogenase/reductase 9, phospholipase A2 group IVE and platelet derived growth factor B were downregulated, while 17 other genes were upregulated in MEF cells. Treatment with AOB markedly increased the expression of phosphorylated extracellular signal‑regulated kinase (ERK), β‑catenin, transcription factor SOX‑17, calcium‑binding tyrosine phosphorylation‑regulated protein, and cholesterol side chain cleavage enzyme mitochondrial (P<0.01). Additionally, the ERK pathway inhibitor U0126 and Wnt pathway inhibitor dickkopf‑related protein 1 markedly suppressed the expression of the above genes (P<0.01). AOB may impact the expression of proteins associated with embryonic fibroblast reproduction and embryonic development through activation of the ERK and Wnt signaling pathways, thus influencing cellular processes.

Monitoring p53 by MDM2 and MDMX is required for endocrine pancreas development and function in a spatio-temporal manner.

PubMed

Zhang, Yiwei; Zeng, Shelya X; Hao, Qian; Lu, Hua

2017-03-01

Although p53 is not essential for normal embryonic development, it plays a pivotal role in many biological and pathological processes, including cell fate determination-dependent and independent events and diseases. The expression and activity of p53 largely depend on its two biological inhibitors, MDM2 and MDMX, which have been shown to form a complex in order to tightly control p53 to an undetectable level during early stages of embryonic development. However, more delicate studies using conditional gene-modification mouse models show that MDM2 and MDMX may function separately or synergistically on p53 regulation during later stages of embryonic development and adulthood in a cell and tissue-specific manner. Here, we report the role of the MDM2/MDMX-p53 pathway in pancreatic islet morphogenesis and functional maintenance, using mouse lines with specific deletion of MDM2 or MDMX in pancreatic endocrine progenitor cells. Interestingly, deletion of MDM2 results in defects of embryonic endocrine pancreas development, followed by neonatal hyperglycemia and lethality, by inducing pancreatic progenitor cell apoptosis and inhibiting cell proliferation. However, unlike MDM2-knockout animals, mice lacking MDMX in endocrine progenitor cells develop normally. But, surprisingly, the survival rate of adult MDMX-knockout mice drastically declines compared to control mice, as blockage of neonatal development of endocrine pancreas by inhibition of cell proliferation and subsequent islet dysfunction and hyperglycemia eventually lead to type 1 diabetes-like disease with advanced diabetic nephropathy. As expected, both MDM2 and MDMX deletion-caused pancreatic defects are completely rescued by loss of p53, verifying the crucial role of the MDM2 and/or MDMX in regulating p53 in a spatio-temporal manner during the development, functional maintenance, and related disease progress of endocrine pancreas. Also, our study suggests a possible mouse model of advanced diabetic nephropathy, which is complementary to other established diabetic models and perhaps useful for the development of anti-diabetes therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

BTG/Tob family members Tob1 and Tob2 inhibit proliferation of mouse embryonic stem cells via Id3 mRNA degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yuanfan; Wang, Chenchen; Peking University Stem Cell Research Center, China National Center for International Research, Peking University Health Science Center, Beijing 100191

2015-07-03

The mammalian BTG/Tob family is a group of proteins with anti-proliferative ability, and there are six members including BTG1, BTG2/PC3/Tis21, BTG3/ANA, BTG4/PC3B, Tob1/Tob and Tob2. Among them, Tob subfamily members, specifically Tob1/Tob and Tob2, have the most extensive C-terminal regions. As previously reported, overexpression of BTG/Tob proteins is associated with the inhibition of G1 to S-phase cell cycle progression and decreased cell proliferation in a variety of cell types. Tob subfamily proteins have similar anti-proliferative effects on cell cycle progression in cultured tumor cells. An important unresolved question is whether or not they have function in rapidly proliferating cells, suchmore » as embryonic stem cells (ESCs). Tob1 and Tob2 were expressed ubiquitously in mouse ESCs (mESCs), suggesting a possible role in early embryonic development and mESCs. To address the above question and explore the possible functions of the Tob subfamily in ESCs, we established ESCs from different genotypic knockout inner cell mass (ICM). We found that Tob1{sup −/−}, Tob2{sup −/−}, and Tob1/2 double knockout (DKO, Tob1{sup −/−} & Tob2{sup −/−}) ESCs grew faster than wild type (WT) ESCs without losing pluripotency, and we provide a possible mechanistic explanation for these observations: Tob1 and Tob2 inhibit the cell cycle via degradation of Id3 mRNA, which is a set of directly targeted genes of BMP4 signaling in mESCs that play critical roles in the maintenance of ESC properties. Together, our data suggest that BTG/Tob family protein Tob1 and Tob2 regulation cell proliferation does not compromise the basic properties of mESCs. - Highlights: • We established mouse Tob1/2 double knockout embryonic stem cells. • Tob1 and Tob2 inhibit the proliferation of ESCs without effect on pluripotency. • Tob1 and Tob2 involved in the degradation of Id3 in mESCs.« less

Cloning of ES cells and mice by nuclear transfer.

PubMed

Wakayama, Sayaka; Kishigami, Satoshi; Wakayama, Teruhiko

2009-01-01

We have been able to develop a stable nuclear transfer (NT) method in the mouse, in which donor nuclei are directly injected into the oocyte using a piezo-actuated micromanipulator. Although the piezo unit is a complex tool, once mastered it is of great help not only in NT experiments, but also in almost all other forms of micromanipulation. Using this technique, embryonic stem (ntES) cell lines established from somatic cell nuclei can be generated relatively easily from a variety of mouse genotypes and cell types. Such ntES cells can be used not only for experimental models of human therapeutic cloning but also as a means of preserving mouse genomes instead of preserving germ cells. Here, we describe our most recent protocols for mouse cloning.

Genetic Tools for Self-Organizing Culture of Mouse Embryonic Stem Cells via Small Regulatory RNA-Mediated Technologies, CRISPR/Cas9, and Inducible RNAi.

PubMed

Takata, Nozomu; Sakakura, Eriko; Sakuma, Tetsushi; Yamamoto, Takashi

2017-01-01

Approaches to investigate gene functions in experimental biology are becoming more diverse and reliable. Furthermore, several kinds of tissues and organs that possess their original identities can be generated in petri dishes from stem cells including embryonic, adult and induced pluripotent stem cells. Researchers now have several choices of experimental methods and their combinations to analyze gene functions in various biological systems. Here, as an example we describe one of the better protocols, which combines three-dimensional embryonic stem cell culture with small regulatory RNA-mediated technologies, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), and inducible RNA interference (RNAi). This protocol allows investigation of genes of interest to better understand gene functions in target tissues (or organs) during in vitro development.

Wnt signaling in caudal dysgenesis and diabetic embryopathy

PubMed Central

Pavlinkova, Gabriela; Salbaum, J. Michael; Kappen, Claudia

2010-01-01

Congenital defects are a major complication of diabetic pregnancy, and the leading cause of infant death in the first year of life. Caudal dysgenesis, occurring up to 200-fold more frequently in children born to diabetic mothers, is a hallmark of diabetic pregnancy. Given that there is also an at least 3-fold higher risk for heart defects and neural tube defects, it is important to identify the underlying molecular mechanisms for aberrant embryonic development. We have investigated gene expression in a transgenic mouse model of caudal dysgenesis, and in a pharmacological model using situ hybridization and quantitative real-time PCR. We identify altered expression of several molecules that control developmental processes and embryonic growth. The results from our models point towards major implication of altered Wnt signaling in the pathogenesis of developmental anomalies associated with embryonic exposure to maternal diabetes. PMID:18937363

Generation of mouse chimeras with high contribution of tetraploid embryonic stem cells and embryonic stem cell-fibroblast hybrid cells.

PubMed

Matveeva, Natalia M; Kizilova, Elena A; Serov, Oleg L

2015-01-01

The in vitro long-term cultivation of embryonic stem (ES) cells derived from pre-implantation embryos offers the unique possibility of combining ES cells with pre-implantation embryos to generate chimeras, thus facilitating the creation of a bridge between in vitro and in vivo investigations. Genomic manipulation using ES cells and homologous recombination is one of the most outstanding scientific achievements, resulting in the generation of animals with desirable genome modifications. As such, the generation of ES cells with different ploidy via cell fusion also deserves much attention because this approach allows for the production of chimeras that contain somatic cells with various ploidy. Therefore, this is a powerful tool that can be used to study the role of polyploidy in the normal development of mammals.

Directed Differentiation of Embryonic Stem Cells Using a Bead-Based Combinatorial Screening Method

PubMed Central

Tarunina, Marina; Hernandez, Diana; Johnson, Christopher J.; Rybtsov, Stanislav; Ramathas, Vidya; Jeyakumar, Mylvaganam; Watson, Thomas; Hook, Lilian; Medvinsky, Alexander; Mason, Chris; Choo, Yen

2014-01-01

We have developed a rapid, bead-based combinatorial screening method to determine optimal combinations of variables that direct stem cell differentiation to produce known or novel cell types having pre-determined characteristics. Here we describe three experiments comprising stepwise exposure of mouse or human embryonic cells to 10,000 combinations of serum-free differentiation media, through which we discovered multiple novel, efficient and robust protocols to generate a number of specific hematopoietic and neural lineages. We further demonstrate that the technology can be used to optimize existing protocols in order to substitute costly growth factors with bioactive small molecules and/or increase cell yield, and to identify in vitro conditions for the production of rare developmental intermediates such as an embryonic lymphoid progenitor cell that has not previously been reported. PMID:25251366

Negative regulation of early polyomavirus expression in mouse embryonal carcinoma cells.

PubMed Central

Cremisi, C; Babinet, C

1986-01-01

Embryonal carcinoma cells are resistant to infection by polyomavirus (Py). We showed that this block was partially removed by inhibiting protein synthesis temporarily. The block was also partially removed when Py was coinfected with simian virus 40. Cycloheximide treatment of cells infected with Py mutants able to grow on PCC4 embryonal carcinoma cells led to 3- to 10-fold increases in the production of T-antigen-positive cells. At 31 degrees C, Py T-antigen expression was enhanced when the cells were treated with cycloheximide. We suggest that a negative labile regulatory protein(s) is synthesized in PCC4 cells, preventing the initiation of early Py transcription by binding to the noncoding sequence, especially the enhancer element B and perhaps also element A, and that the Py mutants retained a binding site(s). PMID:3016339

The Phosphatase PTP-PEST/PTPN12 Regulates Endothelial Cell Migration and Adhesion, but Not Permeability, and Controls Vascular Development and Embryonic Viability*

PubMed Central

Souza, Cleiton Martins; Davidson, Dominique; Rhee, Inmoo; Gratton, Jean-Philippe; Davis, Elaine C.; Veillette, André

2012-01-01

Protein-tyrosine phosphatase (PTP)-PEST (PTPN12) is ubiquitously expressed. It is essential for normal embryonic development and embryonic viability in mice. Herein we addressed the involvement of PTP-PEST in endothelial cell functions using a combination of genetic and biochemical approaches. By generating primary endothelial cells from an inducible PTP-PEST-deficient mouse, we found that PTP-PEST is not needed for endothelial cell differentiation and proliferation or for the control of endothelial cell permeability. Nevertheless, it is required for integrin-mediated adhesion and migration of endothelial cells. PTP-PEST-deficient endothelial cells displayed increased tyrosine phosphorylation of Cas, paxillin, and Pyk2, which were previously also implicated in integrin functions. By eliminating PTP-PEST in endothelial cells in vivo, we obtained evidence that expression of PTP-PEST in endothelial cells is required for normal vascular development and embryonic viability. Therefore, PTP-PEST is a key regulator of integrin-mediated functions in endothelial cells seemingly through its capacity to control Cas, paxillin, and Pyk2. This function explains at least in part the essential role of PTP-PEST in embryonic development and viability. PMID:23105101

[Regulation of in vitro and in vivo differentiation of mouse embryonic stem cells, embryonic germ cells, and teratocarcinoma cells by TGFb family signaling factors].

PubMed

Gordeeva, O F; Nikonova, T M; Lifantseva, N V

2009-01-01

The activity of specific signaling and transcription factors determines the cell fate in normal development and in tumor transformation. The transcriptional profiles of gene-components of different branches of TGFbeta family signaling pathways were studied in experimental models of initial stages of three-dimensional in vitro differentiation of embryonic stem cells, embryonic germ cells and teratocarcinoma cells and in teratomas and teratocarcinomas developed after their transplantation into immunodeficient Nude mice. Gene profile analysis of studied cell systems have revealed that expression patterns of ActivinA, Nodal, Lefty1, Lefty2, TGF TGFbeta1, BMP4, and GDF were identical in pluripotent stem cells whereas the mRNAs of all examined genes with the exception of Inhibin betaA/ActivinA were detected in the teratocarcinoma cells. These results indicate that differential activity of signaling pathways of the TGFbeta family factors regulates pluripotent state maintenance and pluripotent stem cell differentiation into the progenitors of three germ layers and extraembryonic structures and that normal expression pattern of TGFbeta family factors is rearranged in embryonic teratocarcinoma cells during tumor growth in vitro and in vivo.

The profile of repeat-associated histone lysine methylation states in the mouse epigenome

PubMed Central

Martens, Joost H A; O'Sullivan, Roderick J; Braunschweig, Ulrich; Opravil, Susanne; Radolf, Martin; Steinlein, Peter; Jenuwein, Thomas

2005-01-01

Histone lysine methylation has been shown to index silenced chromatin regions at, for example, pericentric heterochromatin or of the inactive X chromosome. Here, we examined the distribution of repressive histone lysine methylation states over the entire family of DNA repeats in the mouse genome. Using chromatin immunoprecipitation in a cluster analysis representing repetitive elements, our data demonstrate the selective enrichment of distinct H3-K9, H3-K27 and H4-K20 methylation marks across tandem repeats (e.g. major and minor satellites), DNA transposons, retrotransposons, long interspersed nucleotide elements and short interspersed nucleotide elements. Tandem repeats, but not the other repetitive elements, give rise to double-stranded (ds) RNAs that are further elevated in embryonic stem (ES) cells lacking the H3-K9-specific Suv39h histone methyltransferases. Importantly, although H3-K9 tri- and H4-K20 trimethylation appear stable at the satellite repeats, many of the other repeat-associated repressive marks vary in chromatin of differentiated ES cells or of embryonic trophoblasts and fibroblasts. Our data define a profile of repressive histone lysine methylation states for the repetitive complement of four distinct mouse epigenomes and suggest tandem repeats and dsRNA as primary triggers for more stable chromatin imprints. PMID:15678104

Simultaneous suppression of TGF-β and ERK signaling contributes to the highly efficient and reproducible generation of mouse embryonic stem cells from previously considered refractory and non-permissive strains.

PubMed

Hassani, Seyedeh-Nafiseh; Totonchi, Mehdi; Farrokhi, Ali; Taei, Adeleh; Larijani, Mehran Rezaei; Gourabi, Hamid; Baharvand, Hossein

2012-06-01

Mouse embryonic stem cells (ESCs) are pluripotent stem cell lines derived from pre-implantation embryos. The efficiency of mESC generation is affected by genetic variation in mice; that is, some mouse strains are refractory or non-permissive to ESC establishment. Developing an efficient method to derive mESCs from strains of various genetic backgrounds should be valuable for establishment of ESCs in various mammalian species. In the present study, we identified dual inhibition of TGF-β and ERK1/2, by SB431542 and PD0325901, respectively led to the highly efficient and reproducible generation of mESC lines from NMRI, C57BL/6, BALB/c, DBA/2, and FVB/N strains, which previously considered refractory or non-permissive for ESC establishment. These mESCs expressed pluripotency markers and retained the capacity to differentiate into derivatives of all three germ layers. The evaluated lines exhibited high rates of chimerism when reintroduced into blastocysts. To our knowledge, this is the first report of efficient (100%) mESC lines generation from different genetic backgrounds. The application of these two inhibitors will not only solve the problems of mESC derivation but also clarifies new signaling pathways in pluripotent mESCs.

Scanning Thin-Sheet Laser Imaging Microscopy Elucidates Details on Mouse Ear Development

PubMed Central

Kopecky, Benjamin; Johnson, Shane; Schmitz, Heather; Santi, Peter; Fritzsch, Bernd

2016-01-01

Background The mammalian inner ear is transformed from a flat placode into a three-dimensional (3D) structure with six sensory epithelia that allow for the perception of sound and both linear and angular acceleration. While hearing and balance problems are typically considered to be adult onset diseases, they may arise as a developmental perturbation to the developing ear. Future prevention of hearing or balance loss requires an understanding of how closely genetic mutations in model organisms reflect the human case, necessitating an objective multidimensional comparison of mouse ears with human ears that have comparable mutations in the same gene. Results Here, we present improved 3D analyses of normal murine ears during embryonic development using optical sections obtained through Thin-Sheet Laser Imaging Microscopy. We chronicle the transformation of an undifferentiated otic vesicle between mouse embryonic day 11.5 to a fully differentiated inner ear at postnatal day 15. Conclusions Our analysis of ear development provides new insights into ear development, enables unique perspectives into the complex development of the ear, and allows for the first full quantification of volumetric and linear aspects of ear growth. Our data provide the framework for future analysis of mutant phenotypes that are currently under-appreciated using only two dimensional renderings. PMID:22271591

A method for deriving homogenous population of oligodendrocytes from mouse embryonic stem cells.

PubMed

Neman, J; de Vellis, J

2012-06-01

There is a pressing need for new therapeutics for the generation and transplantation of oligodendrocyte to the white matter to help replace and render injured cells that are lost in demyelinating disease. There are a few protocols describing a homogenous derivation of non-manipulated mouse embryonic stem cells to oligodendrocytes (ES-OL). Moreover, protocols that are successful in producing ES-OL do so with low efficiency. Therefore, we describe clear methodology for differentiation of mouse ES cells to oligodendrocyte to a high degree of homogenity and reproducibility in vitro. In addition, taking advantage of three defined media, we can generate a defined ES to oligodendrocyte lineage while selecting against neurons and astrocytes. More specifically, (1) Glial stem cell defining media (GSCDM), supplemented with appropriate combination of SHH and RA support pro-oligodendrocyte developing neural spheres from ES cells, (2) Oligodendrocyte differentiating media, induces lineage selection of oligodendrocytes progenitors from neural stem cells, and (3) Oligodendrocyte maturation media, supports oligodendrocytes progenitor maturation. Moreover, the ES cell derived oligodendrocytes display mature properites in the prescence of rat dorsal root gangila in vitro. Thus confirming thier potential for use to invesitgate developmental pathways and future potential use of cells in transplantation towards myelin repair. Copyright © 2012 Wiley Periodicals, Inc.

Striking a balance: regulation of transposable elements by Zfp281 and Mll2 in mouse embryonic stem cells

PubMed Central

Dai, Qian; Shen, Yang; Wang, Yan; Wang, Xin; Francisco, Joel Celio; Luo, Zhuojuan

2017-01-01

Abstract Transposable elements (TEs) compose about 40% of the murine genome. Retrotransposition of active TEs such as LINE-1 (L1) tremendously impacts genetic diversification and genome stability. Therefore, transcription and transposition activities of retrotransposons are tightly controlled. Here, we show that the Krüppel-like zinc finger protein Zfp281 directly binds and suppresses a subset of retrotransposons, including the active young L1 repeat elements, in mouse embryonic stem (ES) cells. In addition, we find that Zfp281-regulated L1s are highly enriched for 5-hydroxymethylcytosine (5hmC) and H3K4me3. The COMPASS-like H3K4 methyltransferase Mll2 is the major H3K4me3 methylase at the Zfp281-regulated L1s and required for their proper expression. Our studies also reveal that Zfp281 functions partially through recruiting the L1 regulators DNA hydroxymethylase Tet1 and Sin3A, and restricting Mll2 at these active L1s, leading to their balanced expression. In summary, our data indicate an instrumental role of Zfp281 in suppressing the young active L1s in mouse ES cells. PMID:29036642

Expression patterns of protein C inhibitor in mouse development.

PubMed

Wagenaar, Gerry T M; Uhrin, Pavel; Weipoltshammer, Klara; Almeder, Marlene; Hiemstra, Pieter S; Geiger, Margarethe; Meijers, Joost C M; Schöfer, Christian

2010-02-01

Proteolysis of extracellular matrix is an important requirement for embryonic development and is instrumental in processes such as morphogenesis, angiogenesis, and cell migration. Efficient remodeling requires controlled spatio-temporal expression of both the proteases and their inhibitors. Protein C inhibitor (PCI) effectively blocks a range of serine proteases, and recently has been suggested to play a role in cell differentiation and angiogenesis. In this study, we mapped the expression pattern of PCI throughout mouse development using in situ hybridization and immunohistochemistry. We detected a wide-spread, yet distinct expression pattern with prominent PCI levels in skin including vibrissae, and in fore- and hindgut. Further sites of PCI expression were choroid plexus of brain ventricles, heart, skeletal muscles, urogenital tract, and cartilages. A strong and stage-dependent PCI expression was observed in the developing lung. In the pseudoglandular stage, PCI expression was present in distal branching tubules whereas proximal tubules did not express PCI. Later in development, in the saccular stage, PCI expression was restricted to distal bronchioli whereas sacculi did not express PCI. PCI expression declined in postnatal stages and was not detected in adult lungs. In general, embryonic PCI expression indicates multifunctional roles of PCI during mouse development. The expression pattern of PCI during lung development suggests its possible involvement in lung morphogenesis and angiogenesis.

Angiogenesis within the developing mouse neural tube is dependent on sonic hedgehog signaling: possible roles of motor neurons.

PubMed

Nagase, Takashi; Nagase, Miki; Yoshimura, Kotaro; Fujita, Toshiro; Koshima, Isao

2005-06-01

Embryonic morphogenesis of vascular and nervous systems is tightly coordinated, and recent studies revealed that some neurogenetic factors such as Sonic hedgehog (Shh) also exhibit angiogenetic potential. Vascularization within the developing mouse neural tube depends on vessel sprouting from the surrounding vascular plexus. Previous studies implicated possible roles of VEGF/Flk-1 and Angiopoietin-1(Ang-1)/Tie-2 signaling as candidate molecules functioning in this process. Examining gene expressions of these factors at embryonic day (E) 9.5 and 10.5, we unexpectedly found that both VEGF and Ang-1 were expressed in the motor neurons in the ventral neural tube. The motor neurons were indeed located in the close vicinity of the infiltrating vessels, suggesting involvement of motor neurons in the sprouting. To substantiate this possibility, we inhibited induction of the motor neurons in the cultured mouse embryos by cyclopamine, a Shh signaling blocker. The vessel sprouting was dramatically impaired by inhibition of Shh signaling, together with nearly complete loss of the motor neurons. Expression of Ang-1, but not VEGF, within the neural tube was remarkably reduced in the cyclopamine treated embryos. These results suggest that the neural tube angiogenesis is dependent on Shh signaling, and mediated, at least in part, by the Ang-1 positive motor neurons.

Scanning thin-sheet laser imaging microscopy elucidates details on mouse ear development.

PubMed

Kopecky, Benjamin; Johnson, Shane; Schmitz, Heather; Santi, Peter; Fritzsch, Bernd

2012-03-01

The mammalian inner ear is transformed from a flat placode into a three-dimensional (3D) structure with six sensory epithelia that allow for the perception of sound and both linear and angular acceleration. While hearing and balance problems are typically considered to be adult onset diseases, they may arise as a developmental perturbation to the developing ear. Future prevention of hearing or balance loss requires an understanding of how closely genetic mutations in model organisms reflect the human case, necessitating an objective multidimensional comparison of mouse ears with human ears that have comparable mutations in the same gene. Here, we present improved 3D analyses of normal murine ears during embryonic development using optical sections obtained through Thin-Sheet Laser Imaging Microscopy. We chronicle the transformation of an undifferentiated otic vesicle between mouse embryonic day 11.5 to a fully differentiated inner ear at postnatal day 15. Our analysis of ear development provides new insights into ear development, enables unique perspectives into the complex development of the ear, and allows for the first full quantification of volumetric and linear aspects of ear growth. Our data provide the framework for future analysis of mutant phenotypes that are currently under-appreciated using only two dimensional renderings. Copyright © 2012 Wiley Periodicals, Inc.

Striking a balance: regulation of transposable elements by Zfp281 and Mll2 in mouse embryonic stem cells.

PubMed

Dai, Qian; Shen, Yang; Wang, Yan; Wang, Xin; Francisco, Joel Celio; Luo, Zhuojuan; Lin, Chengqi

2017-12-01

Transposable elements (TEs) compose about 40% of the murine genome. Retrotransposition of active TEs such as LINE-1 (L1) tremendously impacts genetic diversification and genome stability. Therefore, transcription and transposition activities of retrotransposons are tightly controlled. Here, we show that the Krüppel-like zinc finger protein Zfp281 directly binds and suppresses a subset of retrotransposons, including the active young L1 repeat elements, in mouse embryonic stem (ES) cells. In addition, we find that Zfp281-regulated L1s are highly enriched for 5-hydroxymethylcytosine (5hmC) and H3K4me3. The COMPASS-like H3K4 methyltransferase Mll2 is the major H3K4me3 methylase at the Zfp281-regulated L1s and required for their proper expression. Our studies also reveal that Zfp281 functions partially through recruiting the L1 regulators DNA hydroxymethylase Tet1 and Sin3A, and restricting Mll2 at these active L1s, leading to their balanced expression. In summary, our data indicate an instrumental role of Zfp281 in suppressing the young active L1s in mouse ES cells. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

EFFECTS OF ETHANOL AND HYDROGEN PEROXIDE ON MOUSE LIMB BUD MESENCHYME DIFFERENTIATION AND CELL DEATH

EPA Science Inventory

Many of the morphological defects associated with embryonic alcohol exposure are a result of cell death. During limb development, ethanol administration produces cell death in the limb and digital defects, including postaxial ectrodactyly. Because an accumulation of reactive oxyg...

AN IN VITRO MODEL FOR MURINE URETERIC EPITHELIAL CELLS

EPA Science Inventory

This report presents a model developed to study growth and differentiation of primary cultures of ureteric epithelial cells from embryonic C57BL/6N mouse urinary tracts. Single cells were resuspended in medium and plated onto transwells coated with collagen IV and laminin. Basa...

Prenatal pharmacotherapy rescues brain development in a Down's syndrome mouse model.

PubMed

Guidi, Sandra; Stagni, Fiorenza; Bianchi, Patrizia; Ciani, Elisabetta; Giacomini, Andrea; De Franceschi, Marianna; Moldrich, Randal; Kurniawan, Nyoman; Mardon, Karine; Giuliani, Alessandro; Calzà, Laura; Bartesaghi, Renata

2014-02-01

Intellectual impairment is a strongly disabling feature of Down's syndrome, a genetic disorder of high prevalence (1 in 700-1000 live births) caused by trisomy of chromosome 21. Accumulating evidence shows that widespread neurogenesis impairment is a major determinant of abnormal brain development and, hence, of intellectual disability in Down's syndrome. This defect is worsened by dendritic hypotrophy and connectivity alterations. Most of the pharmacotherapies designed to improve cognitive performance in Down's syndrome have been attempted in Down's syndrome mouse models during adult life stages. Yet, as neurogenesis is mainly a prenatal event, treatments aimed at correcting neurogenesis failure in Down's syndrome should be administered during pregnancy. Correction of neurogenesis during the very first stages of brain formation may, in turn, rescue improper brain wiring. The aim of our study was to establish whether it is possible to rescue the neurodevelopmental alterations that characterize the trisomic brain with a prenatal pharmacotherapy with fluoxetine, a drug that is able to restore post-natal hippocampal neurogenesis in the Ts65Dn mouse model of Down's syndrome. Pregnant Ts65Dn females were treated with fluoxetine from embryonic Day 10 until delivery. On post-natal Day 2 the pups received an injection of 5-bromo-2-deoxyuridine and were sacrificed after either 2 h or after 43 days (at the age of 45 days). Untreated 2-day-old Ts65Dn mice exhibited a severe neurogenesis reduction and hypocellularity throughout the forebrain (subventricular zone, subgranular zone, neocortex, striatum, thalamus and hypothalamus), midbrain (mesencephalon) and hindbrain (cerebellum and pons). In embryonically treated 2-day-old Ts65Dn mice, precursor proliferation and cellularity were fully restored throughout all brain regions. The recovery of proliferation potency and cellularity was still present in treated Ts65Dn 45-day-old mice. Moreover, embryonic treatment restored dendritic development, cortical and hippocampal synapse development and brain volume. Importantly, these effects were accompanied by recovery of behavioural performance. The cognitive deficits caused by Down's syndrome have long been considered irreversible. The current study provides novel evidence that a pharmacotherapy with fluoxetine during embryonic development is able to fully rescue the abnormal brain development and behavioural deficits that are typical of Down's syndrome. If the positive effects of fluoxetine on the brain of a mouse model are replicated in foetuses with Down's syndrome, fluoxetine, a drug usable in humans, may represent a breakthrough for the therapy of intellectual disability in Down's syndrome.

SC1 Promotes MiR124-3p Expression to Maintain the Self-Renewal of Mouse Embryonic Stem Cells by Inhibiting the MEK/ERK Pathway.

PubMed

Wei, Qing; Liu, Hongliang; Ai, Zhiying; Wu, Yongyan; Liu, Yingxiang; Shi, Zhaopeng; Ren, Xuexue; Guo, Zekun

2017-01-01

Self-renewal is one of the most important features of embryonic stem (ES) cells. SC1 is a small molecule modulator that effectively maintains the self-renewal of mouse ES cells in the absence of leukemia inhibitory factor (LIF), serum and feeder cells. However, the mechanism by which SC1 maintains the undifferentiated state of mouse ES cells remains unclear. In this study, microarray and small RNA deep-sequencing experiments were performed on mouse ES cells treated with or without SC1 to identify the key genes and microRNAs that contributed to self-renewal. SC1 regulates the expressions of pluripotency and differentiation factors, and antagonizes the retinoic acid (RA)-induced differentiation in the presence or absence of LIF. SC1 inhibits the MEK/ERK pathway through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and pathway reporting experiments. Small RNA deep-sequencing revealed that SC1 significantly modulates the expression of multiple microRNAs with crucial functions in ES cells. The expression of miR124-3p is upregulated in SC1-treated ES cells, which significantly inhibits the MEK/ERK pathway by targeting Grb2, Sos2 and Egr1. SC1 enhances the self-renewal capacity of mouse ES cells by modulating the expression of key regulatory genes and pluripotency-associated microRNAs. SC1 significantly upregulates miR124-3p expression to further inhibit the MEK/ ERK pathway by targeting Grb2, Sos2 and Egr1. © 2017 The Author(s). Published by S. Karger AG, Basel.

Genetically Engineered Mouse Models for Studying Inflammatory Bowel Disease

PubMed Central

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2015-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. PMID:26387641

Regulation of the epithelial adhesion molecule CEACAM1 is important for palate formation.

PubMed

Mima, Junko; Koshino, Aya; Oka, Kyoko; Uchida, Hitoshi; Hieda, Yohki; Nohara, Kanji; Kogo, Mikihiko; Chai, Yang; Sakai, Takayoshi

2013-01-01

Cleft palate results from a mixture of genetic and environmental factors and occurs when the bilateral palatal shelves fail to fuse. The objective of this study was to search for new genes involved in mouse palate formation. Gene expression of murine embryonic palatal tissue was analyzed at various developmental stages before, during, and after palate fusion using GeneChip® microarrays. Ceacam1 was one of the highly up-regulated genes during palate formation, and this was confirmed by quantitative real-time PCR. Immunohistochemical staining showed that CEACAM1 was present in prefusion palatal epithelium and was degraded during fusion. To investigate the developmental role of CEACAM1, function-blocking antibody was added to embryonic mouse palate in organ culture. Palatal fusion was inhibited by this function-blocking antibody. To investigate the subsequent developmental role of CEACAM1, we characterized Ceacam1-deficient (Ceacam1(-/-)) mice. Epithelial cells persisted abnormally at the midline of the embryonic palate even on day E16.0, and palatal fusion was delayed in Ceacam1(-/-) mice. TGFβ3 expression, apoptosis, and cell proliferation in palatal epithelium were not affected in the palate of Ceacam1(-/-)mice. However, CEACAM1 expression was retained in the remaining MEE of TGFβ-deficient mice. These results suggest that CEACAM1 has roles in the initiation of palatal fusion via epithelial cell adhesion.

Isolating and Analyzing Cells of the Pancreas Mesenchyme by Flow Cytometry.

PubMed

Epshtein, Alona; Sakhneny, Lina; Landsman, Limor

2017-01-28

The pancreas is comprised of epithelial cells that are required for food digestion and blood glucose regulation. Cells of the pancreas microenvironment, including endothelial, neuronal, and mesenchymal cells were shown to regulate cell differentiation and proliferation in the embryonic pancreas. In the adult, the function and mass of insulin-producing cells were shown to depend on cells in their microenvironment, including pericyte, immune, endothelial, and neuronal cells. Lastly, changes in the pancreas microenvironment were shown to regulate pancreas tumorigenesis. However, the cues underlying these processes are not fully defined. Therefore, characterizing the different cell types that comprise the pancreas microenvironment and profiling their gene expression are crucial to delineate the tissue development and function under normal and diseased states. Here, we describe a method that allows for the isolation of mesenchymal cells from the pancreas of embryonic, neonatal, and adult mice. This method utilizes the enzymatic digestion of mouse pancreatic tissue and the subsequent fluorescence-activated cell sorting (FACS) or flow-cytometric analysis of labeled cells. Cells can be labeled by either immunostaining for surface markers or by the expression of fluorescent proteins. Cell isolation can facilitate the characterization of genes and proteins expressed in cells of the pancreas mesenchyme. This protocol was successful in isolating and culturing highly enriched mesenchymal cell populations from the embryonic, neonatal, and adult mouse pancreas.

hnRNP K Coordinates Transcriptional Silencing by SETDB1 in Embryonic Stem Cells

PubMed Central

Thompson, Peter J.; Dulberg, Vered; Moon, Kyung-Mee; Foster, Leonard J.; Chen, Carol; Karimi, Mohammad M.; Lorincz, Matthew C.

2015-01-01

Retrotransposition of endogenous retroviruses (ERVs) poses a substantial threat to genome stability. Transcriptional silencing of a subset of these parasitic elements in early mouse embryonic and germ cell development is dependent upon the lysine methyltransferase SETDB1, which deposits H3K9 trimethylation (H3K9me3) and the co-repressor KAP1, which binds SETDB1 when SUMOylated. Here we identified the transcription co-factor hnRNP K as a novel binding partner of the SETDB1/KAP1 complex in mouse embryonic stem cells (mESCs) and show that hnRNP K is required for ERV silencing. RNAi-mediated knockdown of hnRNP K led to depletion of H3K9me3 at ERVs, concomitant with de-repression of proviral reporter constructs and specific ERV subfamilies, as well as a cohort of germline-specific genes directly targeted by SETDB1. While hnRNP K recruitment to ERVs is dependent upon KAP1, SETDB1 binding at these elements requires hnRNP K. Furthermore, an intact SUMO conjugation pathway is necessary for SETDB1 recruitment to proviral chromatin and depletion of hnRNP K resulted in reduced SUMOylation at ERVs. Taken together, these findings reveal a novel regulatory hierarchy governing SETDB1 recruitment and in turn, transcriptional silencing in mESCs. PMID:25611934

Resolving early mesoderm diversification through single-cell expression profiling.

PubMed

Scialdone, Antonio; Tanaka, Yosuke; Jawaid, Wajid; Moignard, Victoria; Wilson, Nicola K; Macaulay, Iain C; Marioni, John C; Göttgens, Berthold

2016-07-14

In mammals, specification of the three major germ layers occurs during gastrulation, when cells ingressing through the primitive streak differentiate into the precursor cells of major organ systems. However, the molecular mechanisms underlying this process remain unclear, as numbers of gastrulating cells are very limited. In the mouse embryo at embryonic day 6.5, cells located at the junction between the extra-embryonic region and the epiblast on the posterior side of the embryo undergo an epithelial-to-mesenchymal transition and ingress through the primitive streak. Subsequently, cells migrate, either surrounding the prospective ectoderm contributing to the embryo proper, or into the extra-embryonic region to form the yolk sac, umbilical cord and placenta. Fate mapping has shown that mature tissues such as blood and heart originate from specific regions of the pre-gastrula epiblast, but the plasticity of cells within the embryo and the function of key cell-type-specific transcription factors remain unclear. Here we analyse 1,205 cells from the epiblast and nascent Flk1(+) mesoderm of gastrulating mouse embryos using single-cell RNA sequencing, representing the first transcriptome-wide in vivo view of early mesoderm formation during mammalian gastrulation. Additionally, using knockout mice, we study the function of Tal1, a key haematopoietic transcription factor, and demonstrate, contrary to previous studies performed using retrospective assays, that Tal1 knockout does not immediately bias precursor cells towards a cardiac fate.

Regulating RNA polymerase pausing and transcription elongation in embryonic stem cells

PubMed Central

Min, Irene M.; Waterfall, Joshua J.; Core, Leighton J.; Munroe, Robert J.; Schimenti, John; Lis, John T.

2011-01-01

Transitions between pluripotent stem cells and differentiated cells are executed by key transcription regulators. Comparative measurements of RNA polymerase distribution over the genome's primary transcription units in different cell states can identify the genes and steps in the transcription cycle that are regulated during such transitions. To identify the complete transcriptional profiles of RNA polymerases with high sensitivity and resolution, as well as the critical regulated steps upon which regulatory factors act, we used genome-wide nuclear run-on (GRO-seq) to map the density and orientation of transcriptionally engaged RNA polymerases in mouse embryonic stem cells (ESCs) and mouse embryonic fibroblasts (MEFs). In both cell types, progression of a promoter-proximal, paused RNA polymerase II (Pol II) into productive elongation is a rate-limiting step in transcription of ∼40% of mRNA-encoding genes. Importantly, quantitative comparisons between cell types reveal that transcription is controlled frequently at paused Pol II's entry into elongation. Furthermore, “bivalent” ESC genes (exhibiting both active and repressive histone modifications) bound by Polycomb group complexes PRC1 (Polycomb-repressive complex 1) and PRC2 show dramatically reduced levels of paused Pol II at promoters relative to an average gene. In contrast, bivalent promoters bound by only PRC2 allow Pol II pausing, but it is confined to extremely 5′ proximal regions. Altogether, these findings identify rate-limiting targets for transcription regulation during cell differentiation. PMID:21460038

Comparison of efficiency of terminal differentiation of oligodendrocytes from induced pluripotent stem cells versus embryonic stem cells in vitro.

PubMed

Tokumoto, Yasuhito; Ogawa, Shinichiro; Nagamune, Teruyuki; Miyake, Jun

2010-06-01

Oligodendrocytes are the myelinating cells of the central nervous system (CNS), and defects in these cells can result in the loss of CNS functions. Although oligodendrocyte progenitor cells transplantation therapy is an effective cure for such symptoms, there is no readily available source of these cells. Recent studies have described the generation of induced pluripotent stem cells (iPS cells) from somatic cells, leading to anticipation of this technique as a novel therapeutic tool in regenerative medicine. In this study, we evaluated the ability of iPS cells derived from mouse embryonic fibroblasts to differentiate into oligodendrocytes and compared this with the differential ability of mouse embryonic stem cells (ES cells). Experiments using an in vitro oligodendrocyte differentiation protocol that was optimized to ES cells demonstrated that 2.3% of iPS cells differentiated into O4(+) oligodendrocytes compared with 24.0% of ES cells. However, the rate of induction of A2B5(+) oligodendrocyte precursor cell (OPC) was similar for both iPS-derived cells and ES-derived cells (14.1% and 12.6%, respectively). These findings suggest that some intracellular factors in iPS cells inhibit the terminal differentiation of oligodendrocytes from the OPC stage. (c) 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Defined culture medium for stem cell differentiation: applicability of serum-free conditions in the mouse embryonic stem cell test.

PubMed

Riebeling, Christian; Schlechter, Katharina; Buesen, Roland; Spielmann, Horst; Luch, Andreas; Seiler, Andrea

2011-06-01

The embryonic stem cell test (EST) is a validated method to assess the developmental toxicity potency of chemicals. It was developed to reduce animal use and allow faster testing for hazard assessment. The cells used in this method are maintained and differentiated in media containing foetal calf serum. This animal product is of considerable variation in quality, and individual batches require extensive testing for their applicability in the EST. Moreover, its production involves a large number of foetuses and possible animal suffering. We demonstrate the serum-free medium and feeder cell-free maintenance of the mouse embryonic stem cell line D3 and investigate the use of specific growth factors for induction of cardiac differentiation. Using a combination of bone morphogenetic protein-2, bone morphogenetic protein-4, activin A and ascorbic acid, embryoid bodies efficiently differentiated into contracting myocardium. Additionally, examining levels of intracellular marker proteins by flow cytometry not only confirmed differentiation into cardiomyocytes, but demonstrated significant differentiation into neuronal cells in the same time frame. Thus, this approach might allow for simultaneous detection of developmental effects on both early mesodermal and neuroectodermal differentiation. The serum-free conditions for maintenance and differentiation of D3 cells described here enhance the transferability and standardisation and hence the performance of the EST. Copyright © 2011 Elsevier Ltd. All rights reserved.