The relationship between intracellular calcium levels and limb bud chondrogenesis in vitro

Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 73-81
Author(s):  
J.A. Bee ◽  
R. Jeffries
Keyword(s):  
Phenotypic Expression ◽  
Culture Conditions ◽  
Limb Bud ◽  
Concentration Effects ◽  
Cartilage Differentiation ◽  
Standard Culture ◽  
The Relationship ◽  
Plateau Level

Under standard culture conditions, chondrogenic expression by stage-21 embryonic chick limb bud mesenchyme is dependent upon high cell plating densities. Alternatively, when cultured in suspension aggregating limb bud cells differentiate exclusively as cartilage. We have previously demonstrated that the aggregation of prechondrogenic limb bud cells is specifically mediated by a Ca2+ -dependent mechanism. In the present paper, we examine the involvement of calcium cations in chondrogenic expression in vitro. During cartilage differentiation, we demonstrate that limb bud cells elevate their intracellular Ca2+ levels to achieve a conserved plateau level. This increase in intracellular Ca2+ levels does not occur in sparse cell cultures, which also fail to demonstrate cartilage differentiation. Although elevation of extracellular Ca2+ concentration effects precocious chondrogenesis, ultimately this is substantially lower than in control cultures. In contrast, elevation of intracellular Ca2+ levels by the addition of 0á1 μm-A23187 readily stimulates precocious and extensive cartilage differentiation. 0á1μm-A23187 initially elevates intracellular Ca2+ levels to that required for cartilage differentiation but this then continues to increase concomitant with a reduction in cartilage nodule size. 10μm-retinoic acid completely inhibits chondrogenesis in vitro and elevates intracellular Ca2+ to particularly high levels. Our data indicate the central role of controlled intracellular Ca2+ levels to normal chondrogenic expression. Deviation from this level by cells that either fail to achieve or that exceed it inhibits subsequent cartilage development, and can cause a loss of phenotypic expression by differentiated cartilage.

Studies on the possible role of cyclic AMP in limb morphogenesis and differentiation

Development ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 91-105
Author(s):  
Robert A. Kosher ◽  
Mary P. Savage
Keyword(s):  
Cyclic Amp ◽  
Molecular Level ◽  
Mesenchymal Cells ◽  
Limb Bud ◽  
Limb Morphogenesis ◽  
Cartilage Differentiation ◽  
Negative Effect ◽  
Cyclic Amp Derivatives

Recent studies indicate that one of the major functions of the apical ectodermal ridge (AER) of the embryonic chick limb bud is to maintain mesenchymal cells directly subjacent to it (i.e. cells extending 0·4–0·5 mm from the AER), in a labile, undifferentiated condition, and that when mesenchymal cells are freed from the AER's influence either artificially or as a result of normal polarized proximal to distallimb outgrowth, they are freed to commence cyto-differentiation. In a preliminary attempt to investigate at a molecular level the mechanism by which the AER exerts its ‘negative’ effect on the cytodifferentiation of subjacent mesenchymal cells, we haveexamined the effect of a variety of agents that elevate cyclic AMP levels on the morphogenesis and differentiation of the unspecialized subridge mesoderm in an organ culture system. In vitro in the presence of the AER, undifferentiated subridge mesoderm explants undergo remarkably normal morphogenesis characterized primarily by progressive polarized proximal to distal outgrowth and changes in the contour of the developing explant. In the presence of cyclic AMP derivatives, explants fail to undergo the polarized outgrowth and contour changes characteristic of control explants. In fact, in the presence of dibutyryl-cyclic AMP and theophylline, AER-directed morphogenesis essentially ceases during the first day of culture. The cessation of AER-directed morphogenesis inthe presence of cyclic AMP derivatives is accompanied by the histochemically and biochemically detectable precocious chondrogenic differentiation of the subridge mesenchymal cells. In control explants, cartilage differentiation only occurs in those proximal cellsof the explant which gradually become located greater than 0·4–0·5 mm from the AER. In contrast, in the presence of cyclic AMP derivatives, cartilage differentiation by cells within 0·4–0·5 mm of the AER is detectable from the first day of culture, and by the third day cartilage formation has occurred throughout the entire explant. Overall, these results indicate that elevating the cyclic AMP content of the subridge mesenchymal cells enables the cells to overcome negative influences on cytodifferentiation and the positive influences on morphogenesis being imposed upon them by the AER. On the basis of this observation and previous studies, a testable model on the role of cyclic AMP in limb morphogenesis and differentiation is proposed.

Ectoderm and mesoderm interactions in the limb bud of the chick embryo studied by transfilter cultures: cartilage differentiation and ultrastructural observations

Development ◽  
1980 ◽  
Vol 59 (1) ◽  
pp. 157-173
Author(s):  
Madeleine Gumpel-Pinot
Keyword(s):  
Chick Embryo ◽  
Pore Size ◽  
Limb Bud ◽  
Mesoderm Cell ◽  
Cartilage Differentiation ◽  
Cell Processes ◽  
Upper Face ◽  
Wing Bud

The wing mesoderm of the chick embryo cultured in vitro without ectoderm is able to differentiate into cartilage from stage 17 (Hamburger & Hamilton, 1951). But before this stage the presence of ectoderm is necessary. In transfilter cultures of wing-bud ectoderm and mesoderm, the mesodermal response as measured by chondrogenesis was directly related to the pore size (0·2–1 μm) of the filter. Filters of 0·2 μm pore size and 10 μm thickness gave no increase in chondrogenesis over that of mesoderm cultures alone. The lower face of filters on the upper face of which mesoderm or ectoderm had been cultured was observed by scanning electron microscopy. With ectoderm, no cell processes crossed the filter. In contrast, with mesoderm, cell processes crossed the filter and this was also related to pore size. A good correlation was observed between the mass and density of processes crossing the filter and the mesodermal response. It is concluded that induction of cartilage in limb mesoderm cannot be classified as a ‘long-range transmission’ system. It requires ectoderm and mesoderm to be separated by a very narrow gap and this condition can be brought about in vitro by extension of mesodermal processes through the filter close to the ectoderm. The results are discussed in relation to a possible role of the basement membrane and associated extracellular matrix in limb cartilage induction.

scholarly journals Role of interleukins in the pathogenesis of pulmonary fibrosis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yi Xin She ◽  
Qing Yang Yu ◽  
Xiao Xiao Tang
Keyword(s):  
Pulmonary Fibrosis ◽  
Therapeutic Strategy ◽  
Future Directions ◽  
Regulation Mechanisms ◽  
Underlying Mechanisms ◽  
Multiple Cells ◽  
The Relationship

AbstractInterleukins, a group of cytokines participating in inflammation and immune response, are proved to be involved in the formation and development of pulmonary fibrosis. In this article, we reviewed the relationship between interleukins and pulmonary fibrosis from the clinical, animal, as well as cellular levels, and discussed the underlying mechanisms in vivo and in vitro. Despite the effects of interleukin-targeted treatment on experimental pulmonary fibrosis, clinical applications are lacking and unsatisfactory. We conclude that intervening in one type of interleukins with similar functions in IPF may not be enough to stop the development of fibrosis as it involves a complex network of regulation mechanisms. Intervening interleukins combined with other existing therapy or targeting interleukins affecting multiple cells/with different functions at the same time may be one of the future directions. Furthermore, the intervention time is critical as some interleukins play different roles at different stages. Further elucidation on these aspects would provide new perspectives on both the pathogenesis mechanism, as well as the therapeutic strategy and drug development.

Structure of vegetative organs in essential oil rose under standard culture conditions and long-term conservation in vitro

2021 ◽  
pp. 185-190
Author(s):  
I.V. Mitrofanova ◽  
V.A. Brailko ◽  
N.P. Lesnikova-Sedoshenko ◽  
N.N. Ivanova ◽  
O.V. Mitrofanova
Keyword(s):  
Essential Oil ◽  
Culture Conditions ◽  
Vegetative Organs ◽  
Standard Culture

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.

Copper complexes as antitumor agents: in vitro and in vivo evidences

2021 ◽  
Vol 28 ◽  
Author(s):  
Lucia M. Balsa ◽  
Enrique J. Baran ◽  
Ignacio E. León
Keyword(s):  
Copper Complexes ◽  
Antitumor Agents ◽  
Essential Element ◽  
Design Synthesis ◽  
Copper Compounds ◽  
Comprehensive Knowledge ◽  
The Relationship

: Copper is an essential element for most aerobic organisms, with an important function as a structural and catalytic cofactor, and in consequence, it is implicated in several biological actions. The relevant aspects of chemistry and biochemistry and the importance of copper compounds in medicine give us a comprehensive knowledge of the multifaceted applications of copper in physiology and physiopathology. In this review, we present an outline of the chemistry and the antitumor properties of copper complexes on breast, colon, and lung cancer cells focus on the role of copper in cancer, the relationship between structure-activity, molecular targets, and the study of the mechanism of action involved in its anticancer activity. This overview is expected to contribute to understanding the design, synthesis, uses of copper complexes as antitumor agents in the most common cancers.

The relationship between motor activity and transmural potential difference in the guinea pig intestine in vitro: is there a neural link?

1986 ◽  
Vol 64 (7) ◽  
pp. 993-998 ◽  
Author(s):  
Beverley Greenwood ◽  
Stephanie Diamant ◽  
J. S. Davison
Keyword(s):  
Guinea Pig ◽  
Motor Activity ◽  
Colonic Motility ◽  
Potential Difference ◽  
Histological Data ◽  
The Relationship ◽  
Spontaneous Fluctuations ◽  
Pig Jejunum

The aim of the experiments was to examine, in vitro, the role of the enteric nervous system in the relationship between motor activity and transmural potential difference (PD) in the guinea pig jejunum and colon using the nerve blocking agents tetrodotoxin (TTX) and aconitine. Histological data showed that perfusion of the intestinal segments with gassed Hepes solution was essential for the maintenance of transmural PD. Disruption of the mucosa was associated with a loss of spontaneous fluctuations in transmural PD without any loss of spontaneous motor activity. Under spontaneous conditions, a neural pathway exists linking jejunal and colonic motility with transmural PD. However, in some cases a mechanical link was also apparent, as an attenuated TTX and aconitine–resistant component.

scholarly journals The role of probiotics on the roadmap to a healthy microbiota: a symposium report

2020 ◽  
Vol 1 ◽  
Author(s):  
Stacey Lockyer ◽  
Marisol Aguirre ◽  
Louise Durrant ◽  
Bruno Pot ◽  
Kaori Suzuki
Keyword(s):  
Gut Microbiota ◽  
Endocrine System ◽  
Immune Functions ◽  
Epigenetic Programming ◽  
Microbiome Research ◽  
Probiotic Mechanisms ◽  
The Relationship ◽  
Host Genes

ABSTRACT The ninth International Yakult Symposium was held in Ghent, Belgium in April 2018. Keynote lectures were from Professor Wijmenga on using biobanks to understand the relationship between the gut microbiota and health; and Professor Hill on phage–probiotic interactions. Session one included talks from Professor Plӧsch on epigenetic programming by nutritional and environmental factors; Professor Wilmes on the use of “omics” methodologies in microbiome research and Professor Rescigno on the gut vascular barrier. Session two explored the evidence behind Lactobacillus casei Shirota with Dr Nanno explaining the plasticity in immunomodulation that enables the strain to balance immune functions; Dr Macnaughtan outlining its potential therapeutic use in cirrhosis and Professor Nishida detailing effects in subjects under stress. The third session saw Professor Marchesi describing that both the host genes and the gut microbiota can play a role in cancer; Professor Bergheim highlighting crosstalk between the gut and the liver and Professor Cani describing the relationship between the gut microbiota and the endocrine system. The final session explored probiotic mechanisms, with Professor Lebeer dissecting the challenges in conducting mechanistic studies; Professor Wehkamp describing the mucosal defence system and Professor Van de Wiele detailing methods for modelling the gut microbiota in vitro.

scholarly journals Role of cholesterol synthesis and esterification in the growth of CEM and MOLT4 lymphoblastic cells

1997 ◽  
Vol 321 (3) ◽  
pp. 603-608 ◽  
Author(s):  
Sandra DESSÌ ◽  
Barbara BATETTA ◽  
Alessandra PANI ◽  
Ornella SPANO ◽  
Francesca SANNA ◽  
...  
Keyword(s):  
Cholesterol Synthesis ◽  
Cholesterol Metabolism ◽  
Cell Leukaemia ◽  
Stationary Growth ◽  
Human T Cell ◽  
T Cell Lines ◽  
Lymphoblastic Cells ◽  
The Relationship

CEM and MOLT4 are human T-cell lines isolated from patients with acute cell leukaemia. In culture they show important differences in cholesterol metabolism, CEM being less efficient at synthesizing cholesterol and having a lower activity of 3-hydroxy-3-methylglutaryl-CoA (HMGCoA) reductase. To investigate further the relationship between regulation of intracellular cholesterol metabolism at various steps and rate of cell growth, cholesterol synthesis, esterification and efflux were evaluated in CEM and MOLT4 cells at different times during exponential and stationary growth in vitro. It was shown that, although CEM cells have a lower rate of cholesterol synthesis, they grow at a faster rate than MOLT4 cells. However, CEM cells exhibit an increased capacity to esterify cholesterol associated with a decreased efflux of newly synthesized cholesterol into the medium. These results provide evidence for an association between the capability to synthesize and retain cell cholesterol esters and the growth rate potential.

THE ACTIVITY OF HUMAN FOLLICLE-STIMULATING HORMONE PREPARATIONS AS MEASURED BY A RESPONSE IN VITRO

1971 ◽  
Vol 51 (1) ◽  
pp. 97-107 ◽  
Author(s):  
MARGARET RYLE
Keyword(s):  
Dose Response ◽  
Mode Of Action ◽  
Follicle Stimulating Hormone ◽  
Culture Conditions ◽  
Thymidine Uptake ◽  
Response Curves ◽  
Standard Culture ◽  
Urinary Fsh ◽  
Stimulating Hormone

SUMMARY Experiments were carried out with two highly purified preparations of human follicle-stimulating hormone (FSH), of pituitary and urinary origin. The uptake of [3H]thymidine was used to measure the response of cultured infantile mouse ovaries. The activity of the pituitary FSH did not decline during 7 days' incubation in the standard culture conditions, nor was it reduced by the culture of infantile mouse ovaries in it. It did not stimulate increased thymidine uptake during the 1st day of culture. Thereafter the rate of thymidine uptake per ovary in response to pituitary FSH remained constant until the end of the 4-day culture period. The urinary FSH became progressively less effective after the 2nd day of incubation. The two preparations gave highly significant linear log dose—response curves in the range 0·01 to 0·64 i.u./ml. The results are discussed in relation to the mode of action of FSH.

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