Enhanced RNA and protein synthesis in adipose tissue of rats adapted to periodic hyperphagia

1968 ◽  
Vol 46 (6) ◽  
pp. 903-906 ◽  
Author(s):  
L. Kazdová ◽  
T. Braun ◽  
P. Fábry ◽  
R. Poledne
Keyword(s):  
Protein Synthesis ◽  
Adipose Tissue ◽  
Rna Synthesis ◽  
De Novo ◽  
Specific Activity ◽  
De Novo Synthesis ◽  
Experimental Conditions ◽  
Rna And Protein Synthesis ◽  
Meal Feeding ◽  
The Difference

RNA synthesis measured by the incorporation of orotic acid-6-14C into RNA was investigated in isolated adipose tissue of control rats and of rats adapted to periodic hyperphagia, evoked by meal-feeding (a single 2-h meal per day). Both groups were fasted for 22 h and subsequently fed a measured test meal for another 2 h. It was revealed that 2 and 4 h after feeding there was no significant change in comparison with values during fasting, whereas in tissue of meal-fed rats the specific activity of RNA gradually increased by 22% and 41% respectively. The difference between controls and meal-fed rats was even much more marked if the specific activity of RNA in fat cells, isolated after incubation of the tissue, was measured. A significantly greater response of meal-fed rats was found when protein synthesis and lipogenesis in adipose tissue were assessed under the same experimental conditions. The possibility is discussed that the enhanced RNA and protein synthesis in adipose tissue of meal-fed rats is associated with de novo synthesis of enzymes involved in adaptive hyperlipogenesis.

scholarly journals Effects of cytosine arabinoside on differential gene expression in embryonic neural retina. II. Immunochemical studies on the accumulation of glutamine synthetase.

1977 ◽  
Vol 74 (1) ◽  
pp. 30-42 ◽  
Author(s):  
R E Jones ◽  
A A Moscona
Keyword(s):  
Glutamine Synthetase ◽  
Cytosine Arabinoside ◽  
Rna Synthesis ◽  
De Novo ◽  
Neural Retina ◽  
Experimental Conditions ◽  
Rna And Protein Synthesis ◽  
Differential Gene ◽  
Continuous Presence ◽  
Progressive Accumulation

Cytosine arabinoside (Ara-C) elicits a significant increase in the level of the enzyme glutamine synthetase (GS) while it markedly reduces overall RNA and protein synthesis in cultures of embryonic chick neural retina. This increase was analyzed by radioimmunochemical procedures and compared with the induction of GS by hydrocortisone (HC). Accumulation of GS in Ara-C-treated retinas was found to be due to de novo synthesis of the enzyme; however, unlike the induction of GS by HC, Ara-C caused no measurable increase in the rate of GS synthesis. The results indicate that Ara-C facilitates GS accumulation largely by preventing degradation of the enzyme. Even though Ara-C inhibits the bulk of RNA synthesis in the retina, it does not stop the formation of GS-specific RNA templates. However, the progressive accumulation of these templates does not result in an increased rate of GS synthesis unless Ara-C is withdrawn from such cultures under suitable experimental conditions. Thus, it is suggested that the continuous presence of Ara-C imposes a reversible hindrance at the translational level which limits the rate of GS synthesis. The results demonstrate that the increase in retinal GS elicited by Ara-C is achieved through mechanisms which are quite different from those involved in the hydrocortisone-mediated induction of this enzyme.

Recovery of normal protein synthesis in heat-shocked chicken myotubes by liposome-mediated transfer of mRNAs

1985 ◽  
Vol 63 (3) ◽  
pp. 231-235 ◽  
Author(s):  
Jnanankur Bag
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
De Novo ◽  
Critical Role ◽  
Recovery Process ◽  
De Novo Synthesis ◽  
Normal Pattern ◽  
Large Unilamellar Vesicles

Exposure of chicken myotube culture to 45 °C induced the synthesis of three heat-shock polypeptides of 25 000, 65 000, and 81 000 daltons. Recovery to the normal pattern of protein synthesis was judged by the decrease in the synthesis of heat-shock polypeptides. This recovery to normal protein synthesis required de novo synthesis of mRNAs for normal cellular proteins. Inhibition of RNA synthesis by actinomycin D during recovery at 37 °C blocked the recovery process and resulted in the continued synthesis of heat-shock polypeptides. Large unilamellar vesicles were used to examine the effect of delivery of mRNAs isolated from both normal and heat-shocked myotubes on the recovery of these cells from heat-shock treatment. The results presented here show that liposome-mediated delivery of normal mRNAs to heat-shocked cells relieved the block of recovery by actinomycin. On the other hand, when mRNAs from heat-shocked cells were used during recovery, the synthesis of heat-shock polypeptides was stimulated. These observations suggest that the relative abundance of mRNAs in the cytoplasm plays a critical role in regulating protein synthesis in chicken myotube cultures.

scholarly journals Physiology of Oil Seeds. V. Germination of NC-13 Virginia-type Peanut Seeds in the Presence of Inhibitors and Ethylene.1,2

1975 ◽  
Vol 2 (2) ◽  
pp. 73-77
Author(s):  
D. L. Ketring
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Total Protein ◽  
Rna Synthesis ◽  
De Novo ◽  
Acid Synthesis ◽  
De Novo Synthesis ◽  
Tracer Studies ◽  
Oil Seeds ◽  
Protein And Rna Synthesis

Abstract Control dormant seeds that imbibed water for 16 hr germinated 100% after 10 μ 1/1 C2H4 was applied for 24 hr. Dormant seeds that imbibed cycloheximide (100 μg/ml), 6-methylpurine (50 μ g/ml) and 6-azauracil (50 μ g/ml) for 16 hr did not germinate at either 24 or 48 hr after 10 μ 1/1 ethylene treatment. Both protein- and nucleic acid-synthesis ihhibitors prevented germination induced by ethylene in these dormant seeds. Imbibition of 20 μ M ABA by dormant seeds prevented germination, but this effect was reversed by ethylene. Tracer studies with 14C-amino acids indicate that ABA does not inhibit total protein synthesis, but it does inhibit emergence in the absence of ethylene. In the presence of ABA plus ethylene, emergence occurred, but no change in total protein synthesis was detected. At 8 weeks after harvest, both germination and incorporation of 2–14C-uracil into RNA were inhibited by ABA and stimulated by ethylene. By 17 weeks after harvest, only the inhibition of germination and its reversal by ethylene were notable. However, at 17 weeks after harvest, ethylene enhanced RNA synthesis when germination and protein synthesis were inhibited by cycloheximide. Development of isocitritase activity in the seeds was inhibited by ABA and the inhibition was reversed by ethylene, indicating that de novo synthesis of protein is inhibited by ABA and activated by ethylene in these seeds. The opposite effects of ABA and ethylene on germination, RNA synthesis and isocitritase activity suggest that germination is controlled at the level of RNA and/or protein synthesis in these seeds. The prevention of germination of dormant seeds in the presence of ethylene by protein- and RNA-synthesis ihhibitors supports this suggestion, but the data do not preclude an action of ABA or ethylene prior to detectable affects on RNA or protein synthesis.

FEMALE ENDOCRINE CONTROL MECHANISMS DURING THE NEONATAL PERIOD

1972 ◽  
Vol 70 (2) ◽  
pp. 396-408 ◽  
Author(s):  
K.-D. Schulz ◽  
H. Haarmann ◽  
A. Harland
Keyword(s):  
Protein Synthesis ◽  
Reproductive System ◽  
Rna Synthesis ◽  
Neonatal Period ◽  
High Dose ◽  
Female Reproductive System ◽  
Endocrine Control ◽  
Hypothalamic Region ◽  
Rna And Protein Synthesis ◽  
Physiological Dose

ABSTRACT The present investigation deals with the oestrogen-sensitivity of the female reproductive system during the neonatal period. Newborn female guinea pigs were used as test animals. At different times after a single subcutaneous injection of a physiological dose of 0.1 μg or an unphysiologically high dose of 10 μg 17β-oestradiol/100 g body weight, the RNA- and protein-synthesis was examined in the hypothalamic region, pituitary, cerebral cortex, liver, adrenal gland, ovary and uterus. With a physiological dose an increase in organ weight, protein content, RNA-and protein-synthesis was found only in the uterus. These alterations turned out to be dose-dependent. In addition to the findings in the uterus an inhibition of the aminoacid incorporation rate occurred in the liver following the injection of the high oestradiol dose. As early as 1 hour after the administration of 0.1 μg 17β-oestradiol an almost 100% increase in uterine protein synthesis was detectable. This result demonstrates a high oestrogen-sensitivity of this organ during the neonatal period. All the other organs of the female reproductive system such as the hypothalamus, pituitary and ovary did not show any oestrogen response. Therefore the functional immaturity of the uterus during post partem life is not the result of a deficient hormone sensitivity but is correlated with the absence of a sufficient hormonal stimulus at this time. The investigation on the effects of actinomycin resulted in different reactions in the uterus and liver. In contrast to the liver a paradoxical actinomycin effect was found in the uterus after treatment with actinomycin alone. This effect is characterized by a small inhibition of RNA-synthesis and a 50% increase in protein synthesis. The treatment of the newborn test animals with actinomycin and 17β-oestradiol together abolished the oestrogen-induced stimulation of the uterine RNA-and protein-synthesis. Consequently, the effect of oestrogens during the neonatal period is also connected with the formation of new proteins via an increased DNA-directed RNA-synthesis.

Rates of de novo Synthesis of Malate Synthase and Albumins during the Very Early Phase of Germination

1979 ◽  
Vol 34 (12) ◽  
pp. 1237-1242 ◽  
Author(s):  
Wolfram Köller ◽  
Helmut Kindl
Keyword(s):  
Early Phase ◽  
De Novo ◽  
Specific Activity ◽  
Specific Radioactivity ◽  
Malate Synthase ◽  
Polyacrylamide Gel ◽  
De Novo Synthesis ◽  
Albumin Fraction ◽  
Average Value ◽  
Large Pool

Abstract Malate synthase is synthesized de novo in the very early phase of germination. Its molecular and immunological properties do not differ from those of malate synthase from fully developed cotyledons. Radioactive leucine was administered to dry seeds of cucumber, and its incorporation into proteins of cotyledons was examined after 2 days of germination. The specific radioactivity of malate synthase, purified by immunoprecipitation and electrophoresis on polyacrylamide gel, was only 1/20 the average value of the total albumin fraction. The minimal incorporation documented by the comparatively low specific activity of isolated malate synthase is discussed in relation to the large pool of malate synthase already present in dry seeds.

scholarly journals Sphingolipid Profiling Reveals Different Extent of Ceramide Accumulation in Bovine Retroperitoneal and Subcutaneous Adipose Tissues

Metabolites ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 473
Author(s):  
Yue Hei Leung ◽  
Sonja Christiane Bäßler ◽  
Christian Koch ◽  
Theresa Scheu ◽  
Ulrich Meyer ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
De Novo ◽  
Specific Activity ◽  
Multiple Reaction Monitoring ◽  
De Novo Synthesis ◽  
Bioactive Lipids ◽  
Tissue Specific ◽  
Sphingosine 1 Phosphate ◽  
Ceramide Accumulation ◽  
Subcutaneous Adipose

Sphingolipids are bioactive lipids that can modulate insulin sensitivity, cellular differentiation, and apoptosis in a tissue-specific manner. However, their comparative profiles in bovine retroperitoneal (RPAT) and subcutaneous adipose tissue (SCAT) are currently unknown. We aimed to characterize the sphingolipid profiles using a targeted lipidomics approach and to assess whether potentially related sphingolipid pathways are different between SCAT and RPAT. Holstein bulls (n = 6) were slaughtered, and SCAT and RPAT samples were collected for sphingolipid profiling. A total of 70 sphingolipid species were detected and quantified by UPLC-MS/MS in multiple reaction monitoring (MRM) mode, including ceramide (Cer), dihydroceramide (DHCer), sphingomyelin (SM), dihydrosphingomyelin (DHSM), ceramide-1-phosphate (C1P), sphingosine-1-phosphate (S1P), galactosylceramide (GalCer), glucosylceramide (GluCer), lactosylceramide (LacCer), sphinganine (DHSph), and sphingosine (Sph). Our results showed that sphingolipids of the de novo synthesis pathway, such as DHSph, DHCer, and Cer, were more concentrated in RPAT than in SCAT. Sphingolipids of the salvage pathway and the sphingomyelinase pathway, such as Sph, S1P, C1P, glycosphingolipid, and SM, were more concentrated in SCAT. Our results indicate that RPAT had a greater extent of ceramide accumulation, thereby increasing the concentration of further sphingolipid intermediates in the de novo synthesis pathway. This distinctive sphingolipid distribution pattern in RPAT and SCAT can potentially explain the tissue-specific activity in insulin sensitivity, proinflammation, and oxidative stress in RPAT and SCAT.

Regulation of the Synthesis of Ribulose-l,5-bisphosphate Carboxylase and Its Subunits in the Flagellate Chlorogonium elongatum. II. Coordinated Synthesis of the Large and Small Subunits

1981 ◽  
Vol 36 (11-12) ◽  
pp. 942-950 ◽  
Author(s):  
Peter Westhoff ◽  
Kurt Zimmermann ◽  
Frank Boege ◽  
Klaus Zetsche
Keyword(s):  
Rna Synthesis ◽  
De Novo ◽  
Fold Increase ◽  
Growth Conditions ◽  
Autotrophic Growth ◽  
De Novo Synthesis ◽  
Bisphosphate Carboxylase ◽  
Unicellular Green Alga ◽  
Protein And Rna Synthesis ◽  
Ribulosebisphosphate Carboxylase

Abstract Transfer of heterotrophically grown cells of the unicellular green alga Chlorogonium elongatum to autotrophic growth conditions causes a 10 -15 fold increase in the amount of the chloroplastic enzyme ribulose-1,5-bisphosphate carboxylase. This increase was found to be due to de novo synthesis. The relative proportions of large and small subunits of the enzyme do not change. Their ratio is close to 3.4, the proportions in weight of the two subunits in the holoenzyme. Continous labelling with [35S]sulfate reveals that the ratios of incorporation into large and small subunits are essentially the same in autotrophic and heterotrophic cells. Pulse-chase experiments show that the subunits are degraded synchronously. The coordinated subunit synthesis cannot be uncoupled using inhibitors of protein and RNA synthesis or high temperature of cultivation of the alga. The results suggests a very tightly coordinated synthesis of the large and small subunits of ribulosebisphosphate carboxylase.

scholarly journals Regulation of CXCR6 Expression on Adipocytes and Osteoblasts Differentiated from Human Adipose Tissue-Derived Mesenchymal Stem Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Seung-Cheol Lee ◽  
Yoo-Jung Lee ◽  
Min Kyoung Shin ◽  
Jung-Suk Sung
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Adipose Tissue ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Human Mesenchymal Stem Cells ◽  
De Novo Synthesis ◽  
Differentiation Potential ◽  
Differentiated Cells

Human mesenchymal stem cells derived from adipose tissue (hADMSCs) are a desirable candidate in regenerative medicine. hADMSCs secrete growth factors, cytokines, and chemokines and also express various receptors that are important in cell activation, differentiation, and migration to injured tissue. We showed that the expression level of chemokine receptor CXCR6 was significantly increased by ~2.5-fold in adipogenic-differentiated cells (Ad), but not in osteogenic-differentiated cells (Os) when compared with hADMSCs. However, regulation of CXCR6 expression on hADMSCs by using lentiviral particles did not affect the differentiation potential of hADMSCs. Increased expression of CXCR6 on Ad was mediated by both receptor recycling, which was in turn regulated by secretion of CXCL16, and de novo synthesis. The level of soluble CXCL16 was highly increased in both Ad and Os in particular, which inversely correlates with the expression on a transmembrane-bound form of CXCL16 that is cleaved by disintegrin and metalloproteinase. We concluded that the expression of CXCR6 is regulated by receptor degradation or recycling when it is internalized by interaction with CXCL16 and by de novo synthesis of CXCR6. Overall, our study may provide an insight into the molecular mechanisms of the CXCR6 reciprocally expressed on differentiated cells from hADMSCs.

scholarly journals Evidence for the De Novo Synthesis of Erythropoietin in Hypoxic Rats

Blood ◽  
1972 ◽  
Vol 40 (5) ◽  
pp. 662-670 ◽  
Author(s):  
J. C. Schooley ◽  
L. J. Mahlmann
Keyword(s):  
Rna Synthesis ◽  
Actinomycin D ◽  
De Novo ◽  
Protein S ◽  
Male Rats ◽  
Hypoxic Exposure ◽  
De Novo Synthesis ◽  
Serum Erythropoietin

Abstract Significant increases in the serum erythropoietin of male rats occur after the end of a brief hypoxic exposure. These increases in the hormone are almost completely abolished when the kidneys are removed after the hypoxic exposure. Injection of puromycin or cycloheximide after the hypoxic exposure significantly decreases the subsequent increases in serum erythropoietin titers, whereas injections of actinomycin D at this time have no significant effect on erythropoietin levels. Injections of actinomycin D before the hypoxic exposure prevent the increase in serum erythropoietin that normally occurs. These findings suggest that a brief period of hypoxia initiates a DNA-dependent RNA synthesis that regulates the de novo ribosomal synthesis of protein(s) involved in the biogenesis of erythropoietin and that the kidney is essential for these reactions to occur.

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