scholarly journals Control of proteoglycan biosynthesis. Further studies on the effect of serum on cultured bovine articular cartilage

1986 ◽  
Vol 237 (3) ◽  
pp. 741-747 ◽  
Author(s):  
D J McQuillan ◽  
C J Handley ◽  
H C Robinson
Keyword(s):  
Articular Cartilage ◽  
Dna Synthesis ◽  
Half Life ◽  
Rna Synthesis ◽  
Core Protein ◽  
Calf Serum ◽  
Proteoglycan Synthesis ◽  
Foetal Calf Serum ◽  
Bovine Articular Cartilage ◽  
Stimulation Of

Proteoglycan synthesis in explant cultures of adult bovine articular cartilage is stimulated in a dose-dependent manner when the tissue is cultured in the presence of foetal-calf serum. The stimulation of proteoglycan synthesis is paralleled by a similar increase in DNA synthesis; however, when DNA synthesis is inhibited by hydroxyurea the stimulation of proteoglycan synthesis by serum remains essentially the same. The apparent half-life of the pool of proteoglycan core protein precursor was measured in freshly isolated tissue as well as in tissue cultured for 7 days in the presence and in the absence of foetal-calf serum; under all conditions the half-life was the same, suggesting that this value is independent of the net rate of proteoglycan synthesis. In the presence of actinomycin D, an inhibitor of RNA synthesis, there was a difference in the apparent half-life of the available pool of mRNA coding for proteoglycan core protein: 8.5 h for tissue maintained in the presence of serum and 3.8 h for tissue cultured in the absence of serum. It is suggested that proteoglycan synthesis is stimulated by serum factors at the level of DNA-dependent RNA synthesis. Concomitant with an increase in the rate of proteoglycan synthesis induced by the presence of serum in the culture medium, an increase in the concentrations of several glycosyltransferases involved in chondroitin sulphate synthesis was also observed.

scholarly journals Template activity of chromatin during stimulation of cellular proliferation in human diploid fibroblasts

1971 ◽  
Vol 122 (2) ◽  
pp. 189-195 ◽  
Author(s):  
John Farber ◽  
Giovanni Rovera ◽  
Renato Baserga
Keyword(s):  
Dna Synthesis ◽  
Rna Synthesis ◽  
Cellular Proliferation ◽  
Calf Serum ◽  
Foetal Calf Serum ◽  
Template Activity ◽  
Diploid Fibroblasts ◽  
Human Diploid Fibroblasts ◽  
Chromatin Template ◽  
Stimulation Of

1. Contact-inhibited confluent monolayers of WI-38 human diploid fibroblasts can be stimulated to divide by replacing the medium with fresh medium containing 30′ foetal calf serum. 2. Of the cells 40–75′ are stimulated to divide with a peak DNA synthesis between 15 and 21h and a peak mitotic index between 28 and 30h after stimulation. 3. In the first 12h before the initiation of DNA synthesis there is a biphasic increase in the incorporation of [3H]uridine into RNA of whole cells. 4. This is paralleled by a similar biphasic stimulation of chromatin template activity measured in vitro in a system in which purified cell chromatin is incubated with an exogenous RNA polymerase isolated from Escherichia coli. 5. The changes in chromatin template activity are believed to represent activation of the genome, with more sites available for RNA synthesis, and to account almost entirely for the changes in RNA synthesis occurring in the whole cell.

scholarly journals Stimulation of proteoglycan biosynthesis by serum and insulin-like growth factor-I in cultured bovine articular cartilage

1986 ◽  
Vol 240 (2) ◽  
pp. 423-430 ◽  
Author(s):  
D J McQuillan ◽  
C J Handley ◽  
M A Campbell ◽  
S Bolis ◽  
V E Milway ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Growth Factor ◽  
Calf Serum ◽  
Proteoglycan Synthesis ◽  
Foetal Calf Serum ◽  
Insulin Like Growth Factor ◽  
Bovine Articular Cartilage ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

The addition of foetal calf serum to explant cultures of adult bovine articular cartilage is known to stimulate proteoglycan synthesis in a dose-dependent manner. We have now shown the activity in serum responsible for this effect to be heat- and acid-stable, to be associated with a high-Mr complex in normal serum but converted to a low-Mr form under acid conditions. The activity has an apparent Mr approximately 10,000 and isoelectric points similar to those reported for insulin-like growth factors (IGFs). Addition of a monoclonal antibody against insulin-like growth factor-I (IGF-I) prevented foetal calf serum from stimulating proteoglycan synthesis. Physiological concentrations of recombinant IGF-I or pharmacological levels of insulin when added to cartilage cultures mimicked the proteoglycan-stimulatory activity of serum. IGF-I appeared to act by increasing the rate of proteoglycan synthesis and did not change the nature of the proteoglycan synthesized nor the rate of proteoglycan catabolism by the tissue, suggesting that IGF-I may be important in the regulation of proteoglycan metabolism in adult articular cartilage. Furthermore, IGF-I can replace foetal calf serum in the culture medium, thereby allowing the use of a fully-defined medium which will maintain the synthesis and tissue levels of proteoglycan in adult articular cartilage explants for up to 5 days.

scholarly journals Modulation of aggrecan and link-protein synthesis in articular cartilage

1992 ◽  
Vol 288 (3) ◽  
pp. 721-726 ◽  
Author(s):  
A J Curtis ◽  
R J Devenish ◽  
C J Handley
Keyword(s):  
Articular Cartilage ◽  
Half Life ◽  
Core Protein ◽  
Calf Serum ◽  
Cartilage Explants ◽  
Dependent Manner ◽  
Link Protein ◽  
The Core ◽  
Explant Cultures ◽  
Igf I

The addition of serum or insulin-like growth factor-I (IGF-I) to the medium of explant cultures of bovine articular cartilage is known to stimulate the synthesis of aggrecan in a dose-dependent manner. The half-life of the pool of proteoglycan core protein was measured in adult articular cartilage cultured for 6 days in the presence and absence of 20 ng of IGF-I/ml and shown to be 24 min under both sets of conditions. The half-life of the mRNA pool coding for aggrecan was also determined and shown to be approx. 4 h in cartilage maintained in culture with or without IGF-I. The pool size of mRNA coding for aggrecan core protein increased 5-6-fold in cartilage explants maintained in culture in medium containing 20% (v/v) fetal-calf serum; however, in tissue maintained with medium containing IGF-I there was no increase in the cellular levels of this mRNA. This suggests that aggrecan synthesis is stimulated by IGF-I at the level of translation of mRNA coding for the core protein of this proteoglycan and that other growth factors are present in serum that stimulate aggrecan synthesis at the level of transcription of the core-protein gene. Inclusion of serum or IGF-I in the medium of cartilage explant cultures induced increases in the amounts of mRNA coding for type II collagen and link protein, whereas only serum enhanced the amount of mRNA for the core protein of decorin.

scholarly journals EFFECT OF GROWTH HORMONE ON THE METABOLISM OF THYMUS AND ON THE IMMUNE RESPONSE AGAINST SHEEP ERYTHROCYTES

1971 ◽  
Vol 134 (5) ◽  
pp. 1095-1113 ◽  
Author(s):  
M. R. Pandian ◽  
G. P. Talwar
Keyword(s):  
Growth Hormone ◽  
Immune Response ◽  
Dna Synthesis ◽  
Rna Synthesis ◽  
Calf Serum ◽  
Lymphoid Organs ◽  
Stimulatory Action ◽  
Early Action ◽  
Stimulation Of

The effect of pituitary growth hormone on the biosynthesis of DNA in the thymus and other lymphoid organs, as well as the ability of the rat to respond immunologically to sheep red blood cells, has been evaluated. There is a marked reduction in plaque-forming cells, hemagglutination titers, and DNA synthesis in animals when examined at 15 wk after hypophysectomy. Administration of bovine growth hormone (BGH) leads to the enhancement of DNA synthesis in lymphoid organs and recovery of the immune response. Similar effects of the hormone are observed in plateaued rats. Injection of rabbit anti-BGH globulins, in contrast to normal rabbit globulins, over 5 days causes a drop in the weight of the thymus and in the rate of DNA synthesis in this organ. The thymus is also the organ in which stimulation of DNA synthesis is observed at a time period earlier than the spleen and lymph nodes after a single injection of BGH. The hormone stimulates not only the incorporation of thymidine-3H into DNA in the cortical cells, but also the incorporation of sodium sulfate-35S into TCA-insoluble biopolymers reported to be elaborated in the medullary area of the thymus. An in vitro system for the action of BGH on the thymus has been described. There is an obligatory requirement for calcium, but not for fetal calf serum in the medium for the hormone effect. An early action of the hormone is the enhanced incorporation of uridine-G-3H into RNA in thymocytes which is followed by a stimulation of the synthesis of proteins and DNA. The stimulatory action of growth hormone on RNA synthesis is not because of a facilitated uptake of the radioactive uridine by the cells under hormonal influence, a mechanism by which insulin is observed to increase RNA synthesis in thymocytes in vitro. The action of growth hormone on thymocytes is specific, since thyroid-stimulating hormone (TSH), luteinizing hormone (LH), and heat-inactivated growth hormone are not effective. BGH has also a beneficial action on the regeneration of the thymus and spleen in starved rats.

Effect of Daunorubicin and Adriamycin on Nucleic ACID Synthesis of Serum Stimulated Mouse Embryo Fibroblasts

1977 ◽  
Vol 63 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Rosanna Supino ◽  
Anna M. Casazza ◽  
Aurelio Di Marco
Keyword(s):  
Dna Synthesis ◽  
Mouse Embryo ◽  
Rna Synthesis ◽  
Calf Serum ◽  
Acid Synthesis ◽  
Anthracycline Antibiotics ◽  
Simple Method ◽  
Mouse Embryo Fibroblasts ◽  
Embryo Fibroblasts

This paper reports the effects of daunorubicin and adriamycin on DNA and RNA synthesis of in vitro cultured mouse embryo fibroblasts (MEF) stimulated by fetal calf serum (FCS). The addition of FCS to quiescent MEF cultures brings about a wave of RNA synthesis, followed by DNA synthesis which starts between 8 and 12 h after change of medium and proceed for up to 24 h. These cells are therefore partially synchronized. The level of DNA synthesis depends on the amount of FCS added. Daunorubicin and adriamycin are almost equally effective in inhibiting DNA synthesis, as well as cell proliferation, which takes place later. Adriamycin is more active than daunorubicin on RNA synthesis. In cultures treated for an 8 h period starting at different times after FCS addition, the highest DNA synthesis inhibition is achieved by treatment during the first 8 h, when DNA synthesis has not yet started. The cellular uptake of daunorubicin is constantly higher than that of adriamycin, in any experimental condition tested. The results show that FCS-stimulated MEF can provide a simple method for studying the effects of anthracycline antibiotics on partially synchronized cells.

Different optimal PHA concentrations for stimulation of Chinese hamster lymphocytes in cultures supplemented with foetal calf serum or horse serum

1982 ◽  
Vol 50 (1) ◽  
pp. 11-15
Author(s):  
B. De Jong ◽  
G.J.P.A. Anders ◽  
I.H. Van Der Meer ◽  
J. Zijlstra ◽  
V.J.S. Idenburg
Keyword(s):  
Horse Serum ◽  
Calf Serum ◽  
Chinese Hamster ◽  
Foetal Calf Serum ◽  
Stimulation Of

scholarly journals Serum factors, growth factors and UDP-sugar metabolism in bovine articular cartilage chondrocytes

1994 ◽  
Vol 303 (3) ◽  
pp. 713-721 ◽  
Author(s):  
G E Ysart ◽  
R M Mason
Keyword(s):  
Growth Factors ◽  
Articular Cartilage ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Sugar Metabolism ◽  
Tgf Beta ◽  
Serum Factors ◽  
Bovine Articular Cartilage ◽  
Stimulation Of

1. The effect of different batches of fetal bovine serum and of growth factors on [35S]sulphate incorporation into glycosaminoglycans and on UDP-sugar pools in explant cultures of bovine articular cartilage was investigated. 2. [35S]Sulphate incorporation was variably stimulated between 1.2- and 3.5-fold by four different batches of serum. The UDP-glucuronate pool size expanded 4.3-6.5-fold in the presence of serum, even in those cultures in which little stimulation of [35S]sulphate incorporation occurred. The UDP-N-acetylhexosamine and UDP-hexose pools expanded by about 1.5- and 2.0-fold respectively in the presence of serum. UDP-xylose was not detected. 3. Equilibrium-labelling and pulse-chase experiments with D-[1-3H]glucose indicated that the rate of flux through the UDP-sugar pools was unaffected by serum. UDP-hexose, UDP-N-acetylhexosamine and UDP-glucuronate have approximate half-lives (t1/2) of 7, 12 and 3-4 min respectively. At equilibrium, the 3H specific activities of UDP-hexose and UDP-N-acetylhexosamine were very similar but that for the UDP-glucuronate pool was much higher, especially in serum-supplemented cultures. The results suggest that UDP-glucuronate synthesis occurs via a pathway which is independent of the main UDP-hexose pathway. 4. Supplementing cultures with heat-treated serum had no effect on the serum-induced expansion of UDP-sugar pools but stimulation of [35S]sulphate incorporation into glycosaminoglycans was 50% lower than for native serum. Acid-treated serum promoted a 2-fold expansion of the UDP-glucuronate and UDP-N-acetylhexosamine pool over that obtained with native serum but was 20% less effective in stimulating [35S]sulphate incorporation than the latter. Prior dialysis of serum had no effect on its modulatory action on either [35S]sulphate incorporation or on the size of UDP-sugar pools. 5. Insulin-like growth factor 1 (IGF-1), transforming growth factor beta-1 (TGF beta-1), platelet-derived growth factor (PDGF) (BB homodimer) and epidermal growth factor (EGF) all stimulated [35S]sulphate incorporation into glycosaminoglycans as expected. The UDP-glucuronate pool expanded by 1.5- and 2.0-fold in the presence of IGF-1 and TGF beta-1 respectively, and by about 1.8-fold in the presence of PDGF or EGF. None of the factors investigated, or combinations of IGF-1 and TGF beta-1 or IGF-1 and EGF, stimulated expansion of the UDP-glucuronate pool to the same extent as native serum.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Stimulation of murine B lymphocytes by isolated C3b.

1975 ◽  
Vol 142 (3) ◽  
pp. 600-610 ◽  
Author(s):  
K U Hartmann ◽  
V A Bokisch
Keyword(s):  
Lymph Node ◽  
Dna Synthesis ◽  
B Lymphocytes ◽  
Cell Cultures ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Lymph Node Cell ◽  
Mouse Strains ◽  
Spleen Cells ◽  
Stimulation Of

Addition of isolated B3b to murine lymph node cell cultures induced increased DNA synthesis. The stimulation is dependent on the dose of C3b added and is potentiated by fetal calf serum present in the medium. Isolated C3 is less stimulatory than C3b; C3a and C3c had no effect on DNA synthesis in these cultures. 10-20% large immunoglobulin containing blastlike cells developed in lymph node cell cultures stimulated by 50 mug C3b in the presence of 3% fetal calf serum. The stimulation by C3b was observed in cultures of lymph node and spleen cells of several mouse strains including C3H/HeJ and congenitally thymus-deficient (nu/nu) mice. The results suggest that B lymphocytes are the main target of the stimulatory effect of C3b. Two mechanisms which may be involved in the stimulation of lymphocytes by C3b are discussed: (a) cross-linking of receptors on the cell surface or between cells, and (b) the binding of C3b to receptors of B lymphocytes and the formation of the complement enzyme C3bB. The results are compatible with the suggestion that activation of C3 is part of the events triggering the B lymphocytes.

A comparison of the synthesis of DNA, RNA and proteins in the embryos of after-ripened and thermo- or FR-dormant Agrostemma githago L. seeds

1995 ◽  
Vol 5 (2) ◽  
pp. 87-97 ◽  
Author(s):  
U. Gerth ◽  
D. Bernhardt
Keyword(s):  
Protein Synthesis ◽  
Dna Synthesis ◽  
Rna Synthesis ◽  
Gradual Decrease ◽  
Two Dimensional ◽  
Dark Incubation ◽  
Low Level ◽  
Developmental Arrest ◽  
Stimulation Of

AbstractImbibed embryos of after-ripened and secondarily thermo- and FR-dormant Agrostemma githago seeds were investigated as to their ability to synthesize DNA, RNA and proteins with the aim of finding characteristic differences connected with the induction and maintenance of developmental arrest. A gradual decrease in DNA synthesis was observed during the induction of thermodormancy. However, DNA synthesis was stimulated up to that of embryos of 30–h-imbibed after-ripened seeds within 24 h approximately after transferring the thermodormant seeds into temperatures which normally allow germination. DNA synthesis of embryos of FR-dormant seeds remained constant at a relatively low level during 7 d FR and another 7 d dark incubation. RNA synthesis decreased to different extents during induction of thermo- and FR-dormancy when it was arrested at a relatively low level in seeds transferred to temperatures which normally allow germination. Processes leading to an increase in RNA synthesis such as in embryos of after-ripened seeds appeared to be quantitatively and/or qualitatively repressed. Interestingly, protein synthesis was extremely depressed during induction of thermodormancy whereas it was slightly stimulated during induction of FR-dormancy. Nevertheless two-dimensional protein PAGE revealed several polypeptides which were new, increased, decreased or not synthesized predominantly in axes of thermo- and FR-dormant seeds in comparison to germinating after-ripened seeds. It is suggested that a connection exists between these polypeptides and the repression of germination. After transferring seconarily dormant seeds to temperatures which normally allow germination, a temporary stimulation of protein synthesis could be observed in both cases.

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