scholarly journals AFFINITY OF ANIMAL CELL NUCLEOLI FOR NORMAL SERUM

1966 ◽  
Vol 29 (3) ◽  
pp. 461-473 ◽  
Author(s):  
John C. Maisel ◽  
Ralph I. Lytle
Keyword(s):  
Serum Proteins ◽  
Animal Cell ◽  
Primary Cultures ◽  
Fluorescence Analysis ◽  
Normal Serum ◽  
Animal Cells ◽  
Sialic Acid Content ◽  
Veronal Buffer ◽  
Nucleolar Component

Nucleoli of animal cells cultured in vitro are modified by a component of "nonimmune" animal serum. Modified nucleoli bind fluorescein-conjugated nonimmune serum proteins, as shown by calcium ion-dependent fluorescence. Analysis of serum indicates that the nucleolar-binding component is a globulin, with an electrophoretic mobility in the same region as the slow alpha-1 component in pH 8.6 Veronal buffer. The component has a low sedimentation constant (2.4S), and appears to contain glycoprotein with relatively high sialic acid content (8.5%); the latter moiety may be essential to reaction with nucleoli. The nucleolar component reacting with this alpha globulin fraction appears to be a histonelike basic protein. Primary cultures of animal cells have been supported for 1 wk through attachment, spreading, and outgrowth from colonies to confluent monolayers in medium containing a nucleolar-reactive serum fraction as the only protein supplement.

scholarly journals Capacity of human serum to depolymerize actin filaments

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 524-530
Author(s):  
PA Janmey ◽  
SE Lind
Keyword(s):  
Human Serum ◽  
Actin Filaments ◽  
Serum Proteins ◽  
Normal Serum ◽  
Slow Phase ◽  
Rapid Phase ◽  
Plasma Gelsolin ◽  
Preferential Formation

Human blood depolymerizes filamentous (F-)actin. The interaction of actin filaments and monomers with human serum was studied by following the kinetics and extent of the depolymerization of pyrene-labeled F- actin and by analysis of serum proteins adhering to immobilized actin monomers. In physiologic Ca2+ concentrations, the depolymerization of F- actin proceeds in two stages: a rapid phase, attributed to direct severing of filaments by plasma gelsolin, and a slow phase attributed to the binding of actin monomers to vitamin D-binding protein (DBP). Without Ca2+, only the slow phase is observed. Human serum can completely depolymerize 10 to 18 mumol/L of actin, of which approximately 5 mumol/L occurs rapidly. Depolymerization can be accounted for by the normal serum concentrations of gelsolin and DBP. Fibrin(ogen) and fibronectin, which bind actin in vitro, do not contribute to the kinetics or extent of its depolymerization. Affinity chromatography and functional assays for the presence of gelsolin-actin complexes show that addition of G-actin to serum results in preferential formation of actin-DBP complexes, but that addition of F- actin to serum produces both gelsolin-actin complexes and DBP-actin complexes. The distinctive binding of actin monomers and polymers to these two serum proteins suggests a means by which their coordinated actions are maximized in vivo, from the standpoint of depolymerizing filaments and clearing monomers from the circulation.

scholarly journals Induction of human monocyte to macrophage maturation in vitro by 1,25- dihydroxyvitamin D3

Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2457-2461 ◽  
Author(s):  
M Kreutz ◽  
R Andreesen
Keyword(s):  
Serum Proteins ◽  
Primary Cultures ◽  
Human Monocyte ◽  
Mononuclear Phagocyte ◽  
Mononuclear Phagocyte System ◽  
Blood Monocytes ◽  
Necrosis Factor Alpha ◽  
Dihydroxyvitamin D3 ◽  
1,25 Dihydroxyvitamin D3

Abstract Cells of the mononuclear phagocyte system arise from circulating blood monocytes (MO) that undergo further maturation on leaving the vasculature and migration into the various tissues and body cavities. This terminal differentiation step is also observed in vitro when blood MO are cultured in the presence of serum. Yet, the inducing signals present in serum are not defined. We have established primary cultures from elutriation-purified blood MO and found that the active metabolite of vitamin D3 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) could induce maturation of MO to macrophages (MAC) in the absence of any serum proteins. Cells were cultured for 7 days with AB-group serum or 1,25(OH)2D3, respectively, and MO maturation analyzed by morphology, functional activity, and the expression of lineage-restricted maturation-associated antigens (MAX.1, MAX.3). At an optimal concentration of 10(-8) mol/L, 1,25(OH)2D3 promoted the development of fully differentiated MAC whose phenotype and functional competence in terms of cytokine release (tumor necrosis factor alpha, interleukin-6, fibronectin, and lysozyme) was comparable with MAC grown in serum. In conclusion, our data may add to the immunoregulatory potential of 1,25(OH)2D3, which may play an essential role in the ontogeny of the mononuclear phagocyte system.

scholarly journals In vitro food production from animal cell cultures as a meat alternative (selected legal aspects)

2020 ◽  
pp. 153-166
Author(s):  
Katarzyna Leśkiewicz
Keyword(s):  
Animal Cell ◽  
Meat Products ◽  
Legal Aspects ◽  
Point Of View ◽  
Animal Cells ◽  
In Vitro Method ◽  
Animal Cell Cultures ◽  
Legal Concepts ◽  
The Eu

From a legal point of view, there may be doubts as to the legal qualification of food obtained in vitro from animal cells. An opinion is expressed in the article that meat from animal cells obtained using the in vitro method does not fall within the classical legal concepts of meat or agricultural production. However, meat products from cells produced by the in vitro method may satisfy the criteria established for novel food. If this is considered to be the correct way of qualification, then they should be subject to the EU market authorisation procedure regulated in Regulation 2015/2283, and a subsequent assessment of their safety. From a legal, economic and social point of view, it is reasonable to produce food using atypical methods if these methods are capable of ensuring food safety.

MEIC Evaluation of Acute Systemic Toxicity

1998 ◽  
Vol 26 (1_suppl) ◽  
pp. 93-129 ◽  
Author(s):  
Cecilia Clemedson ◽  
Frank A. Barile ◽  
Barbro Ekwall ◽  
Maria José Gómez-Lechón ◽  
Tony Hall ◽  
...  
Keyword(s):  
Cell Lines ◽  
Primary Cultures ◽  
Toxicity Testing ◽  
Preceding Paper ◽  
In Vitro Toxicity ◽  
Toxicity Data ◽  
Animal Cells ◽  
Basal Cytotoxicity

Results from tests on the first 30 MEIC reference chemicals in 16 different systems are presented as a prerequisite to the subsequent in vitro/in vivo comparisons of acute toxicity data, i.e. the final MEIC evaluation of all test results of the study. The study is a supplement to the previously published results from 68 methods (including methods 45B and 46B [old numbers]) used to test the same set of chemicals. The strategies and methods of the preceding paper were employed to enable a comparative cytotoxicity analysis of the results from these 68 methods and from the 16 new methods to be made. Principal components analysis (PCA) of 82 assays demonstrated a dominating first component which described as much as 83% of the variance in the toxicity data. This remarkable similarity of all toxicity data was the main finding of the present study, and confirmed the results of the previous study with a less-extensive database. Also, the influence on the general variability of results of several key methodological factors was evaluated by analysis of selected sets of data, including linear regression of the results of pairs of methods, which were similar in all respects except for the factor under analysis. This analysis of the same 82 assays as before also confirmed previous results from the 68 assay database: a) the toxicities of a third of the chemicals increased considerably with exposure time; b) in general, cytotoxicity for human cells was well predicted by cytotoxicity tests with animal cells; c) this prediction was poor for two chemicals, i.e. digoxin and malathion; d) prediction of human cytotoxicity by ecotoxicological tests was only fairly good; e) 25 comparisons of similar assays employing different cell lines showed strikingly similar toxicities (mean R2 = 0.86); f) 22 comparisons of similar pairs of assays employing different primary cultures and cell lines also revealed similar toxicities (mean R2 = 0.79); and g) 15 comparisons of similar assays with different growth/viability endpoint measurements demonstrated strikingly similar toxicities (mean R2 = 0.89). Results b, e, f and g must be the main causes of the general similarity of results, while results a, c and d, together with other factors, could explain the 20% dissimilarity. These findings support the basal cytotoxicity concept and may assist in guiding and refining in vitro toxicity testing in the future.

scholarly journals Induction of human monocyte to macrophage maturation in vitro by 1,25- dihydroxyvitamin D3

Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2457-2461 ◽  
Author(s):  
M Kreutz ◽  
R Andreesen
Keyword(s):  
Serum Proteins ◽  
Primary Cultures ◽  
Human Monocyte ◽  
Mononuclear Phagocyte ◽  
Mononuclear Phagocyte System ◽  
Blood Monocytes ◽  
Necrosis Factor Alpha ◽  
Dihydroxyvitamin D3 ◽  
1,25 Dihydroxyvitamin D3

Cells of the mononuclear phagocyte system arise from circulating blood monocytes (MO) that undergo further maturation on leaving the vasculature and migration into the various tissues and body cavities. This terminal differentiation step is also observed in vitro when blood MO are cultured in the presence of serum. Yet, the inducing signals present in serum are not defined. We have established primary cultures from elutriation-purified blood MO and found that the active metabolite of vitamin D3 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) could induce maturation of MO to macrophages (MAC) in the absence of any serum proteins. Cells were cultured for 7 days with AB-group serum or 1,25(OH)2D3, respectively, and MO maturation analyzed by morphology, functional activity, and the expression of lineage-restricted maturation-associated antigens (MAX.1, MAX.3). At an optimal concentration of 10(-8) mol/L, 1,25(OH)2D3 promoted the development of fully differentiated MAC whose phenotype and functional competence in terms of cytokine release (tumor necrosis factor alpha, interleukin-6, fibronectin, and lysozyme) was comparable with MAC grown in serum. In conclusion, our data may add to the immunoregulatory potential of 1,25(OH)2D3, which may play an essential role in the ontogeny of the mononuclear phagocyte system.

scholarly journals Capacity of human serum to depolymerize actin filaments

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 524-530 ◽  
Author(s):  
PA Janmey ◽  
SE Lind
Keyword(s):  
Human Serum ◽  
Actin Filaments ◽  
Serum Proteins ◽  
Normal Serum ◽  
Slow Phase ◽  
Rapid Phase ◽  
Plasma Gelsolin ◽  
Preferential Formation

Abstract Human blood depolymerizes filamentous (F-)actin. The interaction of actin filaments and monomers with human serum was studied by following the kinetics and extent of the depolymerization of pyrene-labeled F- actin and by analysis of serum proteins adhering to immobilized actin monomers. In physiologic Ca2+ concentrations, the depolymerization of F- actin proceeds in two stages: a rapid phase, attributed to direct severing of filaments by plasma gelsolin, and a slow phase attributed to the binding of actin monomers to vitamin D-binding protein (DBP). Without Ca2+, only the slow phase is observed. Human serum can completely depolymerize 10 to 18 mumol/L of actin, of which approximately 5 mumol/L occurs rapidly. Depolymerization can be accounted for by the normal serum concentrations of gelsolin and DBP. Fibrin(ogen) and fibronectin, which bind actin in vitro, do not contribute to the kinetics or extent of its depolymerization. Affinity chromatography and functional assays for the presence of gelsolin-actin complexes show that addition of G-actin to serum results in preferential formation of actin-DBP complexes, but that addition of F- actin to serum produces both gelsolin-actin complexes and DBP-actin complexes. The distinctive binding of actin monomers and polymers to these two serum proteins suggests a means by which their coordinated actions are maximized in vivo, from the standpoint of depolymerizing filaments and clearing monomers from the circulation.

Pulsatile GnRH secretion from primary cultures of sheep olfactory placode explants

Reproduction ◽  
2000 ◽  
pp. 391-396 ◽  
Author(s):  
AH Duittoz ◽  
M Batailler
Keyword(s):  
Culture Medium ◽  
Primary Cultures ◽  
Pulsatile Secretion ◽  
Olfactory Placode ◽  
Gnrh Secretion ◽  
Individual Culture ◽  
Pulsatile Gnrh

The aim of this study was to investigate the development of pulsatile GnRH secretion by GnRH neurones in primary cultures of olfactory placodes from ovine embryos. Culture medium was collected every 10 min for 8 h to detect pulsatile secretion. In the first experiment, pulsatile secretion was studied in two different sets of cultures after 17 and 24 days in vitro. In the second experiment, a set of cultures was tested after 10, 17 and 24 days in vitro to investigate the development of pulsatile GnRH secretion in each individual culture. This study demonstrated that (i) primary cultures of GnRH neurones from olfactory explants secreted GnRH in a pulsatile manner and that the frequency and mean interpulse duration were similar to those reported in castrated ewes, and (ii) pulsatile secretion was not present at the beginning of the culture but was observed between 17 and 24 days in vitro, indicating the maturation of individual neurones and the development of their synchronization.

Characterization of an Intermediate Filament Protein from the Platyhelminth, Dugesia japonica

2020 ◽  
Vol 27 (5) ◽  
pp. 432-446
Author(s):  
Akiko Yamamoto ◽  
Ken-ichiro Matsunaga ◽  
Toyoaki Anai ◽  
Hitoshi Kawano ◽  
Toshihisa Ueda ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Immunohistochemical Analysis ◽  
Protein Characterization ◽  
Intermediate Filament Protein ◽  
Tail Domain ◽  
Animal Cells ◽  
Dugesia Japonica ◽  
Function Relationship

Background: Intermediate Filaments (IFs) are major constituents of the cytoskeletal systems in animal cells. Objective: To gain insights into the structure-function relationship of invertebrate cytoplasmic IF proteins, we characterized an IF protein from the platyhelminth, Dugesia japonica, termed Dif-1. Method: cDNA cloning, in situ hybridization, immunohistochemical analysis, and IF assembly experiments in vitro using recombinant Dif-1, were performed for protein characterization. Results: The structure deduced from the cDNA sequence showed that Djf-1 comprises 568 amino acids and has a tripartite domain structure (N-terminal head, central rod, and C-terminal tail) that is characteristic of IF proteins. Similar to nuclear IF lamins, Djf-1 contains an extra 42 residues in the coil 1b subdomain of the rod domain that is absent from vertebrate cytoplasmic IF proteins and a nuclear lamin-homology segment of approximately 105 residues in the tail domain; however, it contains no nuclear localization signal. In situ hybridization analysis showed that Djf-1 mRNA is specifically expressed in cells located within the marginal region encircling the worm body. Immunohistochemical analysis showed that Djf-1 protein forms cytoplasmic IFs located close to the microvilli of the cells. In vitro IF assembly experiments using recombinant proteins showed that Djf-1 alone polymerizes into IFs. Deletion of the extra 42 residues in the coil 1b subdomain resulted in the failure of IF formation. Conclusions: Together with data from other histological studies, our results suggest that Djf- 1 is expressed specifically in anchor cells within the glandular adhesive organs of the worm and that Djf-1 IFs may play a role in protecting the cells from mechanical stress.

scholarly journals A Peptide Found in Human Serum, Derived from the C-Terminus of Albumin, Shows Antifungal Activity In Vitro and In Vivo

2020 ◽  
Vol 8 (10) ◽  
pp. 1627
Author(s):  
Tecla Ciociola ◽  
Pier Paolo Zanello ◽  
Tiziana D’Adda ◽  
Serena Galati ◽  
Stefania Conti ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Human Serum ◽  
Fungicidal Activity ◽  
Galleria Mellonella ◽  
Serum Proteins ◽  
Morphological Alterations ◽  
C Terminus ◽  
Different Sources

The growing problem of antimicrobial resistance highlights the need for alternative strategies to combat infections. From this perspective, there is a considerable interest in natural molecules obtained from different sources, which are shown to be active against microorganisms, either alone or in association with conventional drugs. In this paper, peptides with the same sequence of fragments, found in human serum, derived from physiological proteins, were evaluated for their antifungal activity. A 13-residue peptide, representing the 597–609 fragment within the albumin C-terminus, was proved to exert a fungicidal activity in vitro against pathogenic yeasts and a therapeutic effect in vivo in the experimental model of candidal infection in Galleria mellonella. Studies by confocal microscopy and transmission and scanning electron microscopy demonstrated that the peptide penetrates and accumulates in Candida albicans cells, causing gross morphological alterations in cellular structure. These findings add albumin to the group of proteins, which already includes hemoglobin and antibodies, that could give rise to cryptic antimicrobial fragments, and could suggest their role in anti-infective homeostasis. The study of bioactive fragments from serum proteins could open interesting perspectives for the development of new antimicrobial molecules derived by natural sources.

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