Behavioural transformation in chick yolk-sac cells

Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 599-610
Author(s):  
J. Roger Downie
Keyword(s):  
Large Scale ◽  
Culture Conditions ◽  
Yolk Sac ◽  
Vitelline Membrane ◽  
In Ovo ◽  
Epithelial Sheet ◽  
Epithelial Sheets ◽  
Yolk Sac Cells

During the first 3 to 4 days of development in the chick, the extraembryonic part, the yolk-sac, expands to encompass the yolk mass. The yolk-sac, initially a two-layered epithelial sheet, is pulled out by the action of a specialized band of cells at its periphery. These attach to the overlying vitelline membrane and move out over it. However, unincubated blastoderms are not attached to the vitelline membrane, and each comprises a loose assemblage of rounded cells, not an epithelial sheet. The transformation of the unincubated blastoderm into an actively expanding epithelial sheet has been followed in culture, using hanging-drop cultures of fragments to observe large-scale behaviour, and disaggregated blastoderms to observe individual cell behaviour. The timing of events in culture accords well with related events in ovo, and the possibility that in vitro changes are merely a response to culture conditions has been largely excluded. 0−6 h in ovo. No cells attached to the vitelline membrane. All cells loosely attached to one another. 0−6 h in vitro. Cells do not attach to the glass. The cells of disaggregated blastoderms are rounded and stationary. 6−10 h in ovo. Cells at the blastoderm periphery attach to the vitelline membrane inner surface, but expansion does not start. The cells remain loosely attached to one another. 6−10 h in vitro. Cells begin to stick to the glass surface. Cells from disaggregated cultures move around as individuals. They remain rounded with long, narrow filopodia. If two cells collide, the adhesion tends to be brief. 10 + h in ovo. The blastoderm starts to expand rapidly as a cohesive epithelial sheet, pulled by its specialized ‘edge’ cells. All yolk-sac cells become tightly attached to one another. 10 + h in vitro. Blastoderm fragments start to spread rapidly as flattened epithelial sheets. There is no sign of specialized ‘edge’ cells. Cells at the periphery of any fragment take on the role of the edge. Cells from disaggregated cultures flatten out on the glass with wide lamellae all round. When two cells collide, they now tend to stick permanently together. The role of these changes in the mechanics of blastoderm expansion is briefly discussed.

scholarly journals The Role of Pre-Clinical 3-Dimensional Models of Osteosarcoma

2020 ◽  
Vol 21 (15) ◽  
pp. 5499
Author(s):  
Hannah L. Smith ◽  
Stephen A. Beers ◽  
Juliet C. Gray ◽  
Janos M. Kanczler
Keyword(s):  
Three Dimensional ◽  
Chorioallantoic Membrane ◽  
3D Models ◽  
In Ovo ◽  
Future Directions ◽  
3 Dimensional ◽  
In Vivo Animal Models

Treatment for osteosarcoma (OS) has been largely unchanged for several decades, with typical therapies being a mixture of chemotherapy and surgery. Although therapeutic targets and products against cancer are being continually developed, only a limited number have proved therapeutically active in OS. Thus, the understanding of the OS microenvironment and its interactions are becoming more important in developing new therapies. Three-dimensional (3D) models are important tools in increasing our understanding of complex mechanisms and interactions, such as in OS. In this review, in vivo animal models, in vitro 3D models and in ovo chorioallantoic membrane (CAM) models, are evaluated and discussed as to their contribution in understanding the progressive nature of OS, and cancer research. We aim to provide insight and prospective future directions into the potential translation of 3D models in OS.

scholarly journals In vitro Studies on PGC or PGC-Like Cells in Cultured Yolk Sac Cells and Embryonic Stem Cells of the Mouse.

2000 ◽  
Vol 63 (3) ◽  
pp. 229-241 ◽  
Author(s):  
Shin-ichiro NAKAGAWA ◽  
Sakura SABURI ◽  
Keitaro YAMANOUCHI ◽  
Hideaki TOJO ◽  
Chikashi TACHI
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Yolk Sac ◽  
In Vitro Studies ◽  
Yolk Sac Cells

scholarly journals IMMUNE RESPONSES IN VITRO

1971 ◽  
Vol 134 (2) ◽  
pp. 395-416 ◽  
Author(s):  
Carl W. Pierce ◽  
Barbara M. Johnson ◽  
Harriet E. Gershon ◽  
Richard Asofsky
Keyword(s):  
Culture Conditions ◽  
Antibody Concentration ◽  
Spleen Cells ◽  
Immunoglobulin Class ◽  
Cell Densities ◽  
Erythrocyte Antigen ◽  
First Time ◽  
Kinetics Of

We have demonstrated for the first time that mouse spleen cells stimulated in vitro with heterologous erythrocytes developed immunoglobulin class-specific γM, γ1, γ2a+2b, and γA plaque-forming cell (PFC) responses. A modification of the hemolytic plaque technique, the addition of goat anti-mouse µ-chain antibody to the assay preparation, specifically prevented development of all γM PFC and enabled accurate and reproducible enumeration of immunoglobulin class-specific PFC after treatment with appropriate monospecific anti-globulins and complement. Culture conditions, with regard to medium, atmosphere, agitation, and spleen cell densities, were similar to those previously shown to support only γM PFC responses. Evaluation of the kinetics of appearance of PFC showed that γM PFC reached maximum numbers on days 4–5; the magnitude of this response was 3–10 times greater than γ1 γ2a+2b, or γA PFC which reached maximum numbers on days 5–6. Optimal erythrocyte antigen dose for γM PFC responses was 107/culture, whereas a dose of 106 erythrocytes/culture consistently stimulated optimal γ1 γ2a+2b, or γA PFC responses. Investigations of the effects of anti-erythrocyte antibody on γM and γG PFC responses indicated that antibody suppressed these responses by neutralizing the effective antigenic stimulus at the macrophage-dependent phase of the response. At the same antibody concentration, γG PFC responses were more effectively suppressed than γM PFC responses. Further, γG responses could be almost completely suppressed by antibody as long as 48 hr after initiation of cultures, whereas γM PFC responses could only be completely suppressed during the first 24 hr. These results were discusssed in terms of the role of antigen in the stimulation γM and γG antibody.

scholarly journals Murine yolk sac endoderm- and mesoderm-derived cell lines support in vitro growth and differentiation of hematopoietic cells

Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2436-2443 ◽  
Author(s):  
MC Yoder ◽  
VE Papaioannou ◽  
PP Breitfeld ◽  
DA Williams
Keyword(s):  
Progenitor Cells ◽  
Cell Lines ◽  
Stromal Cell ◽  
Hematopoietic Cells ◽  
Yolk Sac ◽  
Hematopoietic Progenitor Cells ◽  
Visceral Endoderm ◽  
Hematopoietic Progenitor

Abstract The mechanisms involved in the induction of yolk sac mesoderm into blood islands and the role of visceral endoderm and mesoderm cells in regulating the restricted differentiation and proliferation of hematopoietic cells in the yolk sac remain largely unexplored. To better define the role of murine yolk sac microenvironment cells in supporting hematopoiesis, we established cell lines from day-9.5 gestation murine yolk sac visceral endoderm and mesoderm layers using a recombinant retrovirus vector containing Simian virus 40 large T- antigen cDNA. Obtained immortalized cell lines expressed morphologic and biosynthetic features characteristic of endoderm and mesoderm cells from freshly isolated yolk sacs. Similar to the differentiation of blood island hematopoietic cells in situ, differentiation of hematopoietic progenitor cells in vitro into neutrophils was restricted and macrophage production increased when bone marrow (BM) progenitor cells were cultured in direct contact with immortalized yolk sac cell lines as compared with culture on adult BM stromal cell lines. Yolk sac- derived cell lines also significantly stimulated the proliferation of hematopoietic progenitor cells compared with the adult BM stromal cell lines. Thus, yolk sac endoderm- and mesoderm-derived cells, expressing many features of normal yolk sac cells, alter the growth and differentiation of hematopoietic progenitor cells. These cells will prove useful in examining the cellular interactions between yolk sac endoderm and mesoderm involved in early hematopoietic stem cell proliferation and differentiation.

Fructose 2,6-bisphosphate biosynthesis and regulation of carbohydrate metabolism in Aspergillus oryzae

1998 ◽  
Vol 44 (1) ◽  
pp. 6-11
Author(s):  
Gandhi Rádis-Baptista ◽  
David N. Urquizo Valdivia ◽  
José Abrahão-Neto
Keyword(s):  
Cyclic Amp ◽  
Carbohydrate Metabolism ◽  
Aspergillus Oryzae ◽  
Culture Conditions ◽  
Dependent Protein Kinase ◽  
Fructose 1,6 Bisphosphatase ◽  
Dependent Protein ◽  
Regulation Of Carbohydrate Metabolism

The biosynthesis and role of fructose 2,6-bisphosphate (Fru-2,6-P2) in carbohydrate metabolism during induction of an amylolytic system in Aspergillus oryzae was studied. Fluctuations in Fru-2,6-P2 were not dependent on the external glucose concentration during induction, whereas the level of Fru-2,6-P2 increased significantly when the oxygen concentration was diminished. Phosphofructokinase II (PFK II) of A. oryzae was sensitive to phosphorylation in vitro by the catalytic subunit of cyclic AMP dependent protein kinase, which increased the Vmax (twofold), although the Km (0.7 mM) remained unchanged. Phosphofructokinase I was neither activated by micromolar Fru-2,6-P2 nor inhibited by high ATP concentrations. The activity of fructose-1,6-bisphosphatase (FBPase) was subject to strong inhibition by Fru-2,6-P2. Addition of glucose to cultures under gluconeogenic conditions caused a decrease of approximately 40% in the FBPase activity within 4 min. These results indicate that the effect of Fru-2,6-P2 in A. oryzae could preferentially control gluconeogenesis. The addition of 0.1 M glucose under gluconeogenic culture conditions also showed that Fru-2,6-P2 fluctuations appeared to be, at least in short term, more closely related to temporal changes in the hexose-6-phosphate concentration.Key words: Aspergillus oryzae; fructose-2,6-bisphosphate; phosphofructokinase II (PFK II); cyclic AMP; gluconeogenesis control.

Effect of Temperature on the Growth Response of Salmonella Enteritidis Inoculated onto the Vitelline Membranes of Fresh Eggs

2003 ◽  
Vol 66 (8) ◽  
pp. 1368-1373 ◽  
Author(s):  
G. J. FLEISCHMAN ◽  
C. L. NAPIER ◽  
D. STEWART ◽  
S. A. PALUMBO
Keyword(s):  
Salmonella Enteritidis ◽  
Growth Response ◽  
Effect Of Temperature ◽  
Vitelline Membrane ◽  
Growth Responses ◽  
In Ovo ◽  
Maximum Increase ◽  
Comparison Of The Results ◽  
As If

The growth response of Salmonella Enteritidis (SE) on the vitelline membrane in vitro was studied with the use of a special tube devised specifically for the inoculation of SE onto the vitelline membrane and for the sampling of the yolk near the inoculation site. This latter ability allowed the detection of the movement of SE into the yolk. The growth of SE on the membrane was compared with that of SE inoculated into yolk and albumen in vitro and in ovo in fresh in-shell eggs. The incubation time was 2 days, and the incubation temperatures were 4, 8, 15, 27, and 37°C. Comparison of the results obtained for in vitro growth showed that at 4, 8, and 15°C, SE behaved as if it were in the albumen, with its numbers decreasing over time. At 27 and 37°C, SE grew as if it were in yolk, with a maximum increase of 4.5 log CFU after 2 days at 37°C. In no experiments involving growth on the vitelline membrane did SE appear in the yolk. Comparisons between in vitro and in ovo growth responses of SE in yolk and albumen indicate that SE growth on the membrane parallels that in the in-shell egg.

scholarly journals Role of Hyperglycemia in the Senescence of Mesenchymal Stem Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Min Yin ◽  
Yan Zhang ◽  
Haibo Yu ◽  
Xia Li
Keyword(s):  
Diabetes Mellitus ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Culture Conditions ◽  
Cell Aging ◽  
Immunomodulatory Properties ◽  
Sound Foundation ◽  
Prevalence Of Diabetes Mellitus

The regenerative and immunomodulatory properties of mesenchymal stem cells (MSCs) have laid a sound foundation for their clinical application in various diseases. However, the clinical efficiency of MSC treatments varies depending on certain cell characteristics. Among these, the roles of cell aging or senescence cannot be excluded. Despite their stemness, evidence of senescence in MSCs has recently gained attention. Many factors may contribute to the senescence of MSCs, including MSC origin (biological niche), donor conditions (age, obesity, diseases, or unknown factors), and culture conditions in vitro. With the rapidly increasing prevalence of diabetes mellitus (DM) and gestational diabetes mellitus (GDM), the effects of hyperglycemia on the senescence of MSCs should be evaluated to improve the application of autologous MSCs. This review aims to present the available data on the senescence of MSCs, its relationship with hyperglycemia, and the strategies to suppress the senescence of MSCs in a hyperglycemic environment.

scholarly journals Hepatocyte organoids and cell transplantation: What the future holds

2021 ◽  
Author(s):  
Weng Chuan Peng ◽  
Lianne J. Kraaier ◽  
Thomas A. Kluiver
Keyword(s):  
Cell Transplantation ◽  
Liver Diseases ◽  
Large Scale ◽  
Fetal Liver ◽  
Culture Conditions ◽  
Current State ◽  
Metabolic Gene Expression ◽  
Potential Applications

AbstractHistorically, primary hepatocytes have been difficult to expand or maintain in vitro. In this review, we will focus on recent advances in establishing hepatocyte organoids and their potential applications in regenerative medicine. First, we provide a background on the renewal of hepatocytes in the homeostatic as well as the injured liver. Next, we describe strategies for establishing primary hepatocyte organoids derived from either adult or fetal liver based on insights from signaling pathways regulating hepatocyte renewal in vivo. The characteristics of these organoids will be described herein. Notably, hepatocyte organoids can adopt either a proliferative or a metabolic state, depending on the culture conditions. Furthermore, the metabolic gene expression profile can be modulated based on the principles that govern liver zonation. Finally, we discuss the suitability of cell replacement therapy to treat different types of liver diseases and the current state of cell transplantation of in vitro-expanded hepatocytes in mouse models. In addition, we provide insights into how the regenerative microenvironment in the injured host liver may facilitate donor hepatocyte repopulation. In summary, transplantation of in vitro-expanded hepatocytes holds great potential for large-scale clinical application to treat liver diseases.

scholarly journals C-STEM: ENGINEERING NICHE-LIKE MICRO-COMPARTMENTS FOR OPTIMAL AND SCALE-INDEPENDENT EXPANSION OF HUMAN PLURIPOTENT STEM CELLS IN BIOREACTORS

2021 ◽  
Author(s):  
Philippe J.R. Cohen ◽  
Elisa Luquet ◽  
Justine Pletenka ◽  
Andrea Leonard ◽  
Elise Warter ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Large Scale ◽  
Scale Up ◽  
Three Dimensional ◽  
Culture Conditions ◽  
Human Pluripotent Stem Cells ◽  
Cell Therapies ◽  
Cellular Source

Human pluripotent stem cells (hPSCs) have emerged as the most promising cellular source for cell therapies. To overcome scale up limitations of classical 2D culture systems, suspension cultures have been developed to meet the need of large-scale culture in regenerative medicine. Despite constant improvements, current protocols relying on the generation of micro-carriers or cell aggregates only achieve moderate amplification performance. Here, guided by reports showing that hPSCs can self-organize in vitro into cysts reminiscent of the epiblast stage in embryo development, we developed a physio-mimetic approach for hPSC culture. We engineered stem cell niche microenvironments inside microfluidics-assisted core-shell microcapsules. We demonstrate that lumenized three-dimensional colonies maximize viability and expansion rates while maintaining pluripotency. By optimizing capsule size and culture conditions, we scale-up this method to industrial scale stirred tank bioreactors and achieve an unprecedented hPSC amplification rate of 282-fold in 6.5 days.

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