scholarly journals Deficiency of Zonula Occludens-1 Causes Embryonic Lethal Phenotype Associated with Defected Yolk Sac Angiogenesis and Apoptosis of Embryonic Cells

2008 ◽  
Vol 19 (6) ◽  
pp. 2465-2475 ◽  
Author(s):  
Tatsuya Katsuno ◽  
Kazuaki Umeda ◽  
Takeshi Matsui ◽  
Masaki Hata ◽  
Atsushi Tamura ◽  
...  
Keyword(s):  
Yolk Sac ◽  
Embryonic Cells ◽  
Tissue Organization ◽  
Zonula Occludens ◽  
Cell Remodeling ◽  
Extraembryonic Mesoderm ◽  
Almost All ◽  
Vascular Trees ◽  
Induced Defects

Zonula occludens (ZO)-1/2/3 are the members of the TJ-MAGUK family of membrane-associated guanylate kinases associated with tight junctions. To investigate the role of ZO-1 (encoded by Tjp1) in vivo, ZO-1 knockout (Tjp1−/−) mice were generated by gene targeting. Although heterozygous mice showed normal development and fertility, delayed growth and development were evident from E8.5 onward in Tjp1−/− embryos, and no viable Tjp1−/− embryos were observed beyond E11.5. Tjp1−/− embryos exhibited massive apoptosis in the notochord, neural tube area, and allantois at embryonic day (E)9.5. In the yolk sac, the ZO-1 deficiency induced defects in vascular development, with impaired formation of vascular trees, along with defective chorioallantoic fusion. Immunostaining of wild-type embryos at E8.5 for ZO-1/2/3 revealed that ZO-1/2 were expressed in almost all embryonic cells, showing tight junction-localizing patterns, with or without ZO-3, which was confined to the epithelial cells. ZO-1 deficiency depleted ZO-1-expression without influence on ZO-2/3 expression. In Tjp1+/+ yolk sac extraembryonic mesoderm, ZO-1 was dominant without ZO-2/3 expression. Thus, ZO-1 deficiency resulted in mesoderms with no ZO-1/2/3, associated with mislocalization of endothelial junctional adhesion molecules. As a result, angiogenesis was defected in Tjp1−/− yolk sac, although differentiation of endothelial cells seemed to be normal. In conclusion, ZO-1 may be functionally important for cell remodeling and tissue organization in both the embryonic and extraembryonic regions, thus playing an essential role in embryonic development.

α4-Integrin+ Endothelium Derived from Primate Embryonic Stem Cells Generates Both Primitive and Definitive Hematopoietic Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 683-683
Author(s):  
Gen Shinoda ◽  
Katsutsugu Umeda ◽  
Toshio Heike ◽  
Masato Arai ◽  
Akira Niwa ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Embryonic Stem Cells ◽  
Hematopoietic Cells ◽  
Embryonic Stem ◽  
Yolk Sac ◽  
Almost All ◽  
Definitive Erythropoiesis ◽  
Definitive Hematopoiesis

Abstract The mechanism of commencement of hematopoiesis in blood islands of the yolk sac and the aorta-gonad-mesonephros (AGM) region during primate embryogenesis remains elusive. We previously showed the development of both primitive and definitive hematopoiesis when cynomolgus monkey embryonic stem cells were co-cultured with OP9 stromal cells. In this study, we examined the hematopoietic potential of endothelial cells developing in our coculture system and demonstrated that VE-cadherin+CD45− endothelial cells derived from embryonic stem cells were able to generate primitive and definitive hematopoietic cells sequentially, as revealed by immunostaining of floating erythrocytes and colony-forming assay in cultures. All floating erythrocytes which emerged initially expressed ε- and ζ-globins, while β-globin expression was hardly detected. The percentage of floating erythrocytes positive for β-globin gradually increased thereafter, and almost all erythrocytes were positive by day 40. Meanwhile, expression of ε- and ζ-globins declined gradually. Clonal analysis revealed that single bipotential cells for hematopoietic and endothelial lineages were included in this endothelial cell population. Hemogenic activity of endothelial cells was observed exclusively in the α4-integrin+ subpopulation. RT-PCR data showed that Runx1, a transcriptional factor associated with definitive hematopoiesis, was expressed in the hemogenic α4-integrin+ subpopulation, but not the non-hemogenic α4-integrin− subpopulation among embryonic stem cell-derived endothelial cells. The kinetics of this hemogenic subpopulation was similar to that of hemogenic endothelial cells previously reported in the yolk sac and the AGM region in vivo, in that they emerged only for a limited time. On the other hand, VE-cadherin−CD45−α4-integrin+ cells gave rise to more primitive erythrocytes than VE-cadherin+CD45−α4-integrin+ cells, but hardly contributed to definitive hematopoiesis. These results indicate that VE-cadherin+CD45−α4-integrin+ endothelial cells generate primitive and definitive hematopoietic cells sequentially, while VE-cadherin−CD45−α4-integrin+ cells are primary sources for primitive hematopoiesis. It seems that precursors of primitive and definitive erythropoiesis arise simultaneously but that the definitive precursors require a period of maturation before they differentiated into blood cells. We suggest that a subset of endothelial cells is involved in primitive as well as definitive hematopoiesis during primate embryogenesis, and that α4-integrin marks the hemogenic subpopulation in primates.

scholarly journals STEM-17. NOT ALL GBM STEM CELLS ARE EQUAL: IMPLICATIONS FOR RESEARCH AND THERAPY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii199-ii200
Author(s):  
Luciano Galdieri ◽  
Arijita Jash ◽  
Olga Malkova ◽  
Diane Mao ◽  
Jian Campian ◽  
...  
Keyword(s):  
Stem Cells ◽  
Phenotypic Diversity ◽  
Treatment Resistance ◽  
Surface Markers ◽  
Mass Cytometry ◽  
Pathway Activation ◽  
Almost All ◽  
And Function ◽  
Activation Status

Abstract Glioblastoma (GBM) kills almost all patients within 2 years. A subpopulation of cells, GBM stem cells (GSCs), contributes to treatment resistance and recurrence. A major therapeutic goal is to kill GSCs, but no targeted therapy yet exists. Since their discovery, GSCs have been isolated using single surface markers, such as CD15, CD44, CD133, and a-6 integrin. It remains unknown how these single surface marker-defined GSC populations compare to each other in terms of signal transduction and function and whether expression of different combinations of these markers is associated with distinct phenotypes. Using mass cytometry and fresh operating room specimens, we found that 15 distinct GSC subpopulations exist in vivo and they differ in their MEK/ERK, WNT, and AKT pathway activation status. In culture, some subpopulations were lost and previously undetectable ones materialized. GSCs highly expressing all four surface markers had the greatest self-renewal capacity and in vivo tumorigenicity as well as the strongest WNT pathway activation. This work highlights the signaling and phenotypic diversity in GSC subpopulations, together suggesting that not all GSCs are equivalent. These observations should be considered when studying GSCs in the laboratory, with implications for the development of treatments that target GSCs and prevent tumor recurrence in patients.

Study of yolk-sac endoderm organogenesis in the chick using a specific enzyme (cysteine lyase) as a marker of cell differentiation

Development ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 159-174
Author(s):  
Nelly Bennett
Keyword(s):  
Cell Differentiation ◽  
Blood Cells ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Specific Enzyme ◽  
Cell Proliferation And Differentiation ◽  
Lyase Activity ◽  
Morphological Specialization

The detection of a specific enzyme (cysteine lyase) of the yolk-sac endoderm by a very sensitive method is employed to characterize cell differentiation during the early stages of endoderm organogenesis in the chick. The first cells to contain active cysteine lyase are found in the germ wall at the primitive streak stage. In vivo observations establish a relation between the morphological specialization and organization of endodermal cells, their loss of mitotic activity and the increase in cysteine lyase activity. They suggest an influence of the mesoderm on endoderm differentiation. In vitro experiments confirm the existence in the yolk-sac endoderm of an incompatibility between cell proliferation and differentiation, as well as the action of the mesoderm on both the structural organization of the endoblast and the appearance of cysteine lyase; this last action seems to be due mainly to blood cells; chicken and rabbit blood cells are equally active. The problems of the origin of the endoderm and of the interactions occurring during the organogenesis of the yolk-sac endoderm are discussed.

scholarly journals Two Populations of Glucocorticoid Receptor-Binding Sites in the Male Rat Hippocampal Genome

Endocrinology ◽  
2013 ◽  
Vol 154 (5) ◽  
pp. 1832-1844 ◽  
Author(s):  
J. Annelies E. Polman ◽  
E. Ronald de Kloet ◽  
Nicole A. Datson
Keyword(s):  
Receptor Binding ◽  
Binding Sites ◽  
Glucocorticoid Receptors ◽  
Full Range ◽  
Male Rat ◽  
Motif Analysis ◽  
Wide Range ◽  
Neuronal Processes ◽  
Almost All

Abstract In the present study, genomic binding sites of glucocorticoid receptors (GR) were identified in vivo in the rat hippocampus applying chromatin immunoprecipitation followed by next-generation sequencing. We identified 2470 significant GR-binding sites (GBS) and were able to confirm GR binding to a random selection of these GBS covering a wide range of P values. Analysis of the genomic distribution of the significant GBS revealed a high prevalence of intragenic GBS. Gene ontology clusters involved in neuronal plasticity and other essential neuronal processes were overrepresented among the genes harboring a GBS or located in the vicinity of a GBS. Male adrenalectomized rats were challenged with increasing doses of the GR agonist corticosterone (CORT) ranging from 3 to 3000 μg/kg, resulting in clear differences in the GR-binding profile to individual GBS. Two groups of GBS could be distinguished: a low-CORT group that displayed GR binding across the full range of CORT concentrations, and a second high-CORT group that displayed significant GR binding only after administering the highest concentration of CORT. All validated GBS, in both the low-CORT and high-CORT groups, displayed mineralocorticoid receptor binding, which remained relatively constant from 30 μg/kg CORT upward. Motif analysis revealed that almost all GBS contained a glucocorticoid response element resembling the consensus motif in literature. In addition, motifs corresponding with new potential GR-interacting proteins were identified, such as zinc finger and BTB domain containing 3 (Zbtb3) and CUP (CG11181 gene product from transcript CG11181-RB), which may be involved in GR-dependent transactivation and transrepression, respectively. In conclusion, our results highlight the existence of 2 populations of GBS in the rat hippocampal genome.

METABOLISM OF RAM TESTICULAR SPERMATOZOA IN THE PRESENCE OF TESTOSTERONE AND RELATED STEROIDS

1970 ◽  
Vol 65 (3) ◽  
pp. 565-576 ◽  
Author(s):  
J. K. Voglmayr ◽  
R. N. Murdoch ◽  
I. G. White
Keyword(s):  
Aerobic Glycolysis ◽  
Rete Testis ◽  
Glycolytic Metabolism ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Testicular Spermatozoa ◽  
Almost All ◽  
Oxidation Of Glucose

ABSTRACT The effects of testosterone* and related steroids on the oxidative and glycolytic metabolism of freshly collected ram testicular spermatozoa and of spermatozoa stored under air in rete testis fluid for 3 days at 3°C have been studied. When freshly collected testicular spermatozoa were incubated with glucose under aerobic conditions only a small proportion of the utilized glucose could be accounted for as lactate. The addition of a number of steroids, including testosterone, androstanedione, 5β-androstanedione, androsterone, epiandrosterone and 5β-androsterone, greatly increased aerobic glycolysis, the oxidation of the substrate and the proportion of the utilized substrate converted to lactic acid. After 3 days storage at 3°C, testicular spermatozoa respired at a greater rate than spermatozoa freshly collected from the testes. Although the stimulating effect of steroids on aerobic glycolysis increased after storage, they depressed rather than stimulated the oxidation of glucose by stored testicular spermatozoa. With the exception of androstanedione, which slightly stimulated glycolysis, storage of testicular spermatozoa for 3 days in the presence of steroids did not significantly influence their subsequent metabolism when washed free of the steroids. Both freshly collected and stored ram testicular spermatozoa displayed a marked Pasteur effect, and utilized more glucose and produced more lactate under anaerobic than under aerobic conditions. In the absence of oxygen the steroids did not stimulate glycolysis to any extent. However, epiandrosterone depressed the glycolysis of freshly collected spermatozoa under anaerobic conditions and after storage, 5β-androsterone had a similar effect. Androstanedione, 5β-androstanedione, epiandrosterone and 5β-androsterone were the most effective steroids in altering the metabolism of testicular spermatozoa and, under almost all conditions of incubation, depressed the synthesis of amino acids from glucose. The results suggest that the effects of testosterone and related steroids in vitro may depend on the age of the spermatozoa after their release from the Sertoli cells; the steroid effects may have important consequences in vivo in relation to sperm maturation.

scholarly journals Medicinal Plants Used for the Traditional Management of Diabetes in the Eastern Cape, South Africa: Pharmacology and Toxicology

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2759 ◽  
Author(s):  
Samuel Odeyemi ◽  
Graeme Bradley
Keyword(s):  
South Africa ◽  
Medicinal Plants ◽  
Scientific Evidence ◽  
Traditional Healers ◽  
Bioactive Molecules ◽  
Eastern Cape ◽  
Insulin Mimetic ◽  
Almost All

The use of medicinal plants for the management of diabetes mellitus is on the rise in the developing countries, including South Africa. There is increasing scientific evidence that supports the claims by the traditional healers. In this review, we compare the families of previously reported anti-diabetic plants in the Eastern Cape by rating the anti-diabetic activity, mode of action and also highlight their therapeutic potentials based on the available evidence on their pharmacology and toxicity. Forty-five plants mentioned in ethnobotanical surveys were subjected to a comprehensive literature search in the available electronic databases such as PubMed, ScienceDirect, Google Scholar and Elsevier, by using “plant name” and “family” as the keywords for the primary searches to determine the plants that have been scientifically investigated for anti-diabetic activity. The search returned 25 families with Asteraceae highly reported, followed by Asphodelaceae and Alliaceae. Most of the plants have been studied for their anti-diabetic potentials in vivo and/or in vitro, with most of the plants having a higher percentage of insulin release and inhibition against carbohydrate digesting enzymes as compared with insulin mimetic and peripheral glucose uptake. Almost all the investigated plants also inhibit oxidative stress as part of their hypoglycemic activity with less toxicity. However, the isolation of their bioactive molecules is still lacking. This review provides a resource to enable thorough assessments of the therapeutic profiles of available medicinal plants used for the management of diabetes in the Eastern Cape, South Africa. Further studies such as the identification of the active ingredients of potent plants still need to be carried out; this may lead to new molecules in drug discovery and development.

scholarly journals Comparative Analyses of Single-Cell Transcriptomic Profiles between In Vitro Totipotent Blastomere-like Cells and In Vivo Early Mouse Embryonic Cells

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3111
Author(s):  
Po-Yu Lin ◽  
Denny Yang ◽  
Chi-Hsuan Chuang ◽  
Hsuan Lin ◽  
Wei-Ju Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Single Cell ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Developmental Potential ◽  
Functional Features ◽  
Early Mouse ◽  
Extraembryonic Tissues

The developmental potential within pluripotent cells in the canonical model is restricted to embryonic tissues, whereas totipotent cells can differentiate into both embryonic and extraembryonic tissues. Currently, the ability to culture in vitro totipotent cells possessing molecular and functional features like those of an early embryo in vivo has been a challenge. Recently, it was reported that treatment with a single spliceosome inhibitor, pladienolide B (plaB), can successfully reprogram mouse pluripotent stem cells into totipotent blastomere-like cells (TBLCs) in vitro. The TBLCs exhibited totipotency transcriptionally and acquired expanded developmental potential with the ability to yield various embryonic and extraembryonic tissues that may be employed as novel mouse developmental cell models. However, it is disputed whether TBLCs are ‘true’ totipotent stem cells equivalent to in vivo two-cell stage embryos. To address this question, single-cell RNA sequencing was applied to TBLCs and cells from early mouse embryonic developmental stages and the data were integrated using canonical correlation analyses. Differential expression analyses were performed between TBLCs and multi-embryonic cell stages to identify differentially expressed genes. Remarkably, a subpopulation within the TBLCs population expressed a high level of the totipotent-related genes Zscan4s and displayed transcriptomic features similar to mouse two-cell stage embryonic cells. This study underscores the subtle differences between in vitro derived TBLCs and in vivo mouse early developmental cell stages at the single-cell transcriptomic level. Our study has identified a new experimental model for stem cell biology, namely ‘cluster 3’, as a subpopulation of TBLCs that can be molecularly defined as near totipotent cells.

scholarly journals Cycle initiation and colony formation in culture by murine marrow cells with long-term reconstituting potential in vivo

Blood ◽  
1996 ◽  
Vol 88 (11) ◽  
pp. 4149-4158 ◽  
Author(s):  
M Trevisan ◽  
XQ Yan ◽  
NN Iscove
Keyword(s):  
Colony Formation ◽  
Interleukin 1 ◽  
Methyl Cellulose ◽  
Culture Conditions ◽  
Liquid Suspension ◽  
Almost All ◽  
Marrow Cells

Abstract This investigation was directed at separating long-term reconstituting (LTR) stem cells in normal murine marrow from hematopoietic precursors detectable in short-term assays in vitro and in vivo, and then at determining whether purified LTR cells could themselves form colonies in culture. To do so, it was first necessary to identify culture conditions that would induce their growth while preserving their long- term reconstituting capacity. Marrow was cultured with various cytokines in liquid suspension for 4 days, after which the surviving LTR activity was quantitated in a competitive in vivo assay. Activity was preserved near input levels with combined murine c-kit ligand (KL), interleukin-1 (IL-1), IL-6, and IL-11. When the cultures also included tritiated or unlabeled thymidine, LTR potential was eliminated, indicating that essentially all LTR cells were induced into cell cycle with these cytokines. To purify them, marrow was sorted on the basis of Ly6A expression and Rhodamine 123 retention. The Ly6AhiRh123ls fraction contained 85% of total recovered LTR activity but only 1% of the recovered cells measured by multilineage colony formation in spleens or in vitro. This fraction was cultured in methyl cellulose with KL, IL-1, IL-6, and IL-11 for 4 to 6 days, after which colonies were isolated and injected into mice. High levels of permanent reconstitution were achievable in sublethally irradiated W41/W41 mice after the injection of a single reconstituting unit, and limiting dilution analysis estimated the frequency of multilineage LTR at 1 in 11,200 unpurified adult marrow cells. In either lethally irradiated normal or sublethally irradiated W41/W41 mice, 1-year lymphomyeloid reconstitutions were obtained from 1 in 65 to 84 colonies of 2 to 16 dispersed cells, but not from larger colonies or those with clumped cells. The results establish that resting marrow LTR cells can be separated from almost all of the more advanced clonogenic cells that are still pluripotential, can be induced to cycle in culture by defined cytokines with preservation of their reconstituting potential, and can be manipulated and assayed efficiently at single-cell and colony levels.

scholarly journals DIPG-07. HIGH THROUGHPUT DRUG SCREENING IDENTIFIES POTENTIAL NEW THERAPIES FOR DIFFUSE INTRINSIC PONTINE GLIOMAS (DIPGs)

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii288-iii288
Author(s):  
Dannielle Upton ◽  
Santosh Valvi ◽  
Jie Liu ◽  
Nicole Yeung ◽  
Sandra George ◽  
...  
Keyword(s):  
High Throughput ◽  
Apoptotic Cell ◽  
Safety Data ◽  
Biologically Active ◽  
Orthotopic Model ◽  
High Throughput Drug Screening ◽  
Diffuse Intrinsic Pontine Gliomas ◽  
Almost All

Abstract DIPGs are the most devastating of all brain tumors. There are no effective treatments, hence almost all children will die of their tumor within 12 months. There is an urgent need for novel effective therapies for this aggressive tumor. We performed a high-throughput drug screen with over 3,500 biologically active, clinically approved compounds against a panel of neurosphere-forming DIPG cells. We identified 7 compounds- auranofin, fenretinide, ivermectin, lanatoside, parthenolide, SAHA and mefloquine- that were confirmed to have potent anti-tumor activity against a panel of DIPG-neurospheres, with minimal effect on normal cells. Using cytotoxicity and clonogenic assays, we found that these drugs were able to inhibit DIPG-neurosphere proliferation and colony formation in-vitro. To determine whether the in-vitro efficacy could be replicated in-vivo, we tested the activity of each of these compounds in an orthotopic DIPG model. Of the agents tested, fenretinide and SAHA were the most active anti-tumor agents, significantly enhancing the survival of tumor bearing animals. Mechanistic studies showed fenretinide enhancing apoptotic cell death of DIPG cells via inhibition of PDGFRa transcription and downregulation of the PI3K/AKT/MTOR pathway. We therefore examined the therapeutic efficacy of fenretinide using a second orthotopic model with PDGFRa amplification. We used two different Fenretinide formulations (LYM-X-Sorb and NanoMicelle) which were found to enhance survival. Fenretinide is clinically available with safety data in children. Validation of the activity of Fenretinide in PDGFRa-amplified or overexpressed DIPGs will lead to the development of a clinical trial, allowing the advancement of fenretinide as potentially the first active therapy for DIPG.

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