scholarly journals Stimulation of vascular protein synthesis by activation of oestrogen receptor beta

2001 ◽  
Vol 171 (3) ◽  
pp. 417-423 ◽  
Author(s):  
M Liang ◽  
E Ekblad ◽  
JA Gustafsson ◽  
BO Nilsson
Keyword(s):  
Protein Synthesis ◽  
Protein Expression ◽  
Oestrogen Receptor ◽  
Beta Agonist ◽  
Tissue Homogenate ◽  
Leucine Incorporation ◽  
Ovariectomized Mice ◽  
Sds Page ◽  
Genistein Treatment ◽  
Stimulation Of

The objective of this study was to investigate the effects of oestrogen receptor (ER) beta activation on vascular protein synthesis and protein expression. Nuclear immunoreactivity towards ER beta was observed abundantly in vascular smooth muscle and endothelial cells of mouse aorta. No ER alpha-positive cell nuclei were observed. In aorta from ovariectomized mice, treatment with the selective ER beta agonist genistein (100 nM) for 24 h increased [(3)H]leucine incorporation by about 30%. This effect was prevented by the ER blocker ICI 182780 (10 microM). Although genistein treatment stimulated protein synthesis, it caused no change in total protein determined either by the Lowry method on tissue homogenate or by densitometric scanning of protein bands (10-220 kDa) separated by SDS-PAGE. Separation of [(35)S]methionine-labelled proteins by SDS-PAGE did not reveal the protein(s) stimulated by genistein. DNA synthesis was not affected by 100 nM genistein, suggesting that genistein-induced stimulation of protein synthesis is not part of a growth response. Protein expression, determined by SDS-PAGE, was similar in aorta from ER beta-knockout and wild-type mice, suggesting that expression of vascular proteins does not depend solely on a functional ER beta gene. We suggest that activation of vascular ER beta stimulates synthesis of proteins and that this response is not associated with vascular growth.

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Stimulation of Myoblast Membrane Protein Synthesis by 25-Hydroxy-Vitamin D 3

1989 ◽  
Vol 44 (9-10) ◽  
pp. 807-812
Author(s):  
Teresita Bellido ◽  
Ricardo Boland
Keyword(s):  
Vitamin D ◽  
Protein Synthesis ◽  
Plasma Membranes ◽  
De Novo ◽  
Phosphate Uptake ◽  
Leucine Incorporation ◽  
Similar Treatment ◽  
25 Hydroxy Vitamin D ◽  
Alpha Bungarotoxin ◽  
Stimulation Of

Abstract The effects of 25-hydroxy-vitamin D3 (25 OHD3) on myoblast protein synthesis were studied in connection with its role on muscle cell phosphate metabolism . The sterol markedly increased leucine incorporation into total cell proteins in cultured chick embryo myoblasts. This enhance­ment was greater than that produced by 1,25-dihydroxy-vitamin D3 (1,25(OH)2D3) and occurred prior to a significant stimulation of cell phosphate accumulation. Maximum effects of 25 OHD3 (8 h) on myoblast phosphate uptake were suppressed by cycloheximide indicating that they are mediated by de novo protein synthesis. At a similar treatment period, labelling of myoblasts with [3H]leucine (control) and [14C]leucine (+ 25 OHD3) followed by co-electrophoresis of total protein extracts on SDS-PAGE and isoelectrofocusing gels revealed that the sterol selectively affects the synthesis of proteins of 20 kDa and 50 kDa. These macromolecules were recovered in the microsomal fraction after differential centrifugation of homogenates. Further fractionation of myoblast microsomes on sucrose density gradients show ed co-localization of the 50 kDa and 20 kDa proteins with microsomal subfractions which preferentially bind [3H -alpha]bungarotoxin, suggesting that the proteins induced by 25 OHD3 are associated to plasma membranes and may play a role in the effects of the sterol on cell phosphate uptake.

THYROXINE STIMULATION OF AMINO ACID INCORPORATION INTO MITOCHONDRIAL PROTEIN: DIFFERENCES BETWEEN IN VIVO AND IN VITRO EFFECTS

1973 ◽  
Vol 72 (4) ◽  
pp. 684-696 ◽  
Author(s):  
Amirav Gordon ◽  
Martin I. Surks ◽  
Jack H. Oppenheimer
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Mitochondrial Protein ◽  
Leucine Incorporation ◽  
Mitochondrial Protein Synthesis ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Stimulation Of

ABSTRACT The in vivo and in vitro stimulation of rat hepatic mitochondrial protein synthesis by thyroxine (T4) was compared. In confirmation of Buchanan & Tapley (1966). T4 added to isolated mitochondria rapidly stimulated [14C] leucine incorporation into mitochondrial protein. The in vitro stimulation was reversed after T4 was removed by incubating the mitochondria with bovine serum albumin (BSA). The decrease in T4 stimulation of protein synthesis appeared proportional to the T4 removed by BSA. Thus, it appears probable that exchangeable T4 controls the in vitro system. In contrast, the increase in mitochondrial protein synthesis which was observed 3 to 4 days after pretreatment of hypothyroid rats with labelled and non-radioactive T4 was not reversed by BSA treatment. Moreover, mitochondrial radioactivity could not be extracted with albumin. The in vivo phenomenon does not, therefore, appear to be related to exchangeable hormone in the mitochondria. Furthermore, the estimated quantity of T4 associated with mitochondria after in vivo stimulation was at least two orders of magnitude less than that required to produce comparable stimulation of mitochondrial protein synthesis in vitro. These findings strongly suggest that in vitro and in vivo stimulation of amino acid incorporation by T4 may be mediated by different biochemical mechanisms.

HORMONAL REGULATION OF RNA AND PROTEIN SYNTHESIS IN THE MOUSE MAMMARY GLAND BEFORE AND DURING LACTATION

1971 ◽  
Vol 50 (2) ◽  
pp. 281-291 ◽  
Author(s):  
M. R. BANERJEE ◽  
FERNE M. ROGERS ◽  
D. N. BANERJEE
Keyword(s):  
Protein Synthesis ◽  
Mammary Gland ◽  
Hormonal Regulation ◽  
Rna Synthesis ◽  
Mouse Mammary Gland ◽  
Synthetic Activity ◽  
Tissue Homogenate ◽  
Mammary Tissue ◽  
Leucine Incorporation

SUMMARY As measured by [3H]uridine incorporation in vivo, the low rate of RNA synthesis in the mammary gland of virgin C3H and BALB/c mice increased sixfold in the mammary tissue of 15-day pregnant mice. In the 5-day lactating gland, RNA synthesis was ten times higher than that in virgin mammary tissue. On the 10th day of lactation this increased RNA synthetic activity in the mammary gland was considerably reduced but was still twice that of the mammary tissue of virgin mice. Twenty-four hours after adrenalectomy, RNA synthesis in lactating glands was reduced by over 80%, whereas in the mammary gland before lactation, it was reduced by 20–30% only. A single i.p. injection of 250 μg of cortisol led to a threefold increase of RNA synthesis within 1 to 2 h in lactating glands of adrenalectomized mice; this was followed by a decline. Incorporation of [3H]leucine into trichloroacetic acid-insoluble material from lactating mammary tissue was used as a measure of'total protein' synthesis, and [3H]leucine radioactivity determined in Ca2+−rennin precipitate of 105000 g supernatant of lactating mammary tissue homogenate was used as a measure of casein synthesis. Adrenalectomy caused a 50% reduction of 'total protein' synthesis, whereas synthesis of 'casein-like' phosphoprotein virtually stopped after the operation. The injection of cortisol into adrenalectomized mice induced a selective increase of [3H]leucine incorporation into the casein of lactating glands. The results indicate that RNA synthesis in the mammary tissue is more dependent on adrenal hormones during the functional than the structural state of differentiation. The hormonal regulation of RNA synthesis and its role in milk protein synthesis in the mammary gland in vivo is discussed.

scholarly journals Insulin stimulates synthesis of soluble proteins in isolated rat hepatocytes

1980 ◽  
Vol 190 (3) ◽  
pp. 615-619 ◽  
Author(s):  
R L Clark ◽  
R J Hansen
Keyword(s):  
Protein Synthesis ◽  
Rat Hepatocytes ◽  
Isolated Hepatocytes ◽  
Cellular Protein ◽  
Soluble Proteins ◽  
Leucine Incorporation ◽  
Isolated Rat Hepatocytes ◽  
Hepatic Protein Synthesis ◽  
Isolated Rat ◽  
Stimulation Of

The incorporation of [3H]leucine into soluble cellular protein was measured in isolated hepatocytes at extracellular leucine concentrations ranging from 0.15 to 20.0 mM. Insulin caused a 12—15% stimulation of [3H]leucine incorporation in the presence of high extracellular leucine concentrations. It is concluded that insulin causes a small but significant increase in the rate of hepatic protein synthesis.

scholarly journals Stimulation of protein synthesis in cultured heart muscle cells by glucose

1975 ◽  
Vol 150 (3) ◽  
pp. 405-411 ◽  
Author(s):  
M David ◽  
Y Avi-Dor
Keyword(s):  
Protein Synthesis ◽  
Heart Muscle ◽  
Muscle Cells ◽  
Inhibitory Effect ◽  
Insoluble Fraction ◽  
Leucine Incorporation ◽  
Stimulatory Action ◽  
Heart Muscle Cells ◽  
Effect Of Glucose ◽  
Stimulation Of

Glucose stimulated the rate of incorporation of [3H]leucine into HCLO4-insoluble fraction of cultured rat heart muscle cells under both aerobic and anaerobic conditions. In the aerobic system the incorporation proceeded at a constant rate during 3h of incubation with and without glucose whereas in the anaeorbic system the incorporation ceased after approx. 60 min and could be renewed only by the addition of glucose. No correlation was found to exist between the above effect of glucose on protein synthesis and glucose-dependent changes in the intracellular ATP concentration. The extent of the stimulation of protein synthesis was related to the concentration of glucose. The effect of glucose was suppressed by cycloheximide but was not affected by actinomycin D. Glucose had no effect on the rate of transport of α-aminoisobutyric acid. Mannose also stimulated [3H]leucine incorporation. Substances that did not produce lactate were ineffective. Iodoacetate inhibited the stimulatory effect of glucose, but pyruvate, which by itself had no apprecialbe stimulatory action, relieved the inhibition induced by iodoacetate. There was no concomitant change in the concentration of ATP when iodoacetate inhibition was reversed by pyruvate. L-Lactate or other intermediates of energy metabolism could not relieve the inhibitory effect of iodoacetate.

Phorbol ester stimulates cyclooxygenase-2 expression and prostanoid production in cardiac myocytes

2000 ◽  
Vol 279 (2) ◽  
pp. H719-H725 ◽  
Author(s):  
Ralph Schuette ◽  
Margot C. LaPointe
Keyword(s):  
Protein Synthesis ◽  
Cardiac Myocytes ◽  
Ventricular Myocytes ◽  
Fold Increase ◽  
Cyclooxygenase 2 ◽  
Leucine Incorporation ◽  
P38 Kinase ◽  
Protein Levels ◽  
Cox 2 ◽  
Stimulation Of

Phorbol-12-myristate- 13-acetate (PMA) has been shown to induce hypertrophy of cardiac myocytes. The prostaglandin endoperoxide H synthase isoform 2 (cyclooxygenase-2, COX-2) has been associated with enhanced growth and/or proliferation of several types of cells. Thus we studied whether PMA induces COX-2 and prostanoid products PGE2 and PGF2α in neonatal ventricular myocytes and whether endogenous COX-2 products participate in their growth. In addition, we examined whether PMA affects interleukin-1β (IL-1β) stimulation of COX-2 and PGE2production. PMA (0.1 μmol/l) stimulated growth, as indicated by a 1.6-fold increase in [3H]leucine incorporation. PMA increased COX-2 protein levels 2.8-fold, PGE2 3.7-fold, and PGF2α 2.9-fold. Inhibition of either p38 kinase or protein kinase C (PKC) prevented PMA-stimulated COX-2. Inhibition of COX-2 with either indomethacin or NS-398 had no effect on PMA-stimulated [3H]leucine incorporation. Exogenous administration of PGF2α, but not PGE2, stimulated protein synthesis. Treatment with IL-1β (5 ng/ml) increased COX-2 protein levels 42-fold, whereas cotreatment with IL-1β and PMA stimulated COX-2 protein only 32-fold. IL-1β did not affect control or PMA-stimulated protein synthesis. These findings indicate that: 1) PMA, acting through PKC and p38 kinase, enhances COX-2 expression, but chronic treatment with PMA partially inhibits IL-1β stimulation of COX-2; and 2) exogenous PGF2α is involved in neonatal ventricular myocyte growth but endogenous COX-2 products are not.

scholarly journals Regulation of mammalian protein synthesis in vivo. Protein synthesis in rat liver and kidney after the administration of sublethal doses of cyclohyximide

1976 ◽  
Vol 156 (1) ◽  
pp. 151-157 ◽  
Author(s):  
L I Rothblum ◽  
T M Devlin ◽  
J J Ch'ih
Keyword(s):  
Protein Synthesis ◽  
Specific Radioactivity ◽  
Cellular Protein ◽  
Leucine Incorporation ◽  
Precursor Pool ◽  
Liver And Kidney ◽  
Sublethal Doses ◽  
Mammalian Protein ◽  
Stimulation Of

Protein synthesis in vivo was studied at various times after the administration of sublethal doses of cycloheximide to rats. Cycloheximide caused an inhibition, followed by a dose-and time-dependent stimulation, of incorportation of labelled precursor into proteins of the liver and kidney. The stimulation of protein synthesis at 24h was not due to a change of precursor pool or the specific radioactivity of the precursor used. During the stimulatory period, leucine incorporation into various cellular protein fractions varied; incorporation into total nuclear protein was the most affected.

Inhibition of glucose metabolism by progesterone in adipocytes: role of protein synthesis

1991 ◽  
Vol 69 (12) ◽  
pp. 1861-1867 ◽  
Author(s):  
P. Cordoba ◽  
A. Kaaya ◽  
O. Richard ◽  
M.-Th. Sutter-Dub
Keyword(s):  
Protein Synthesis ◽  
Glucose Metabolism ◽  
Glucose Transport ◽  
Glucose Oxidation ◽  
Actinomycin D ◽  
Inhibitory Effect ◽  
Leucine Incorporation ◽  
Female Rat ◽  
Sds Page

Progesterone decreases [1-14C]glucose oxidation in isolated female rat adipocytes within 20 min of incubation. Because steroids regulate transcription mechanisms, the relationship between protein synthesis and glucose metabolism was studied in the presence of progesterone. Actinomycin D does not affect basal glucose oxidation or the progesterone effects on it; cycloheximide and puromycin decrease basal glucose oxidation, but only puromycin decreases the inhibitory progesterone effect. Although puromycin inhibits glucose transport, the common site of action of puromycin and progesterone does not seem to be glucose transport, which, as we showed previously, is not modified by the steroid. Incorporation of [3H]leucine into acid-precipitable proteins is decreased by puromycin and cycloheximide but not by actinomycin D or progesterone; moreover, the action of these inhibitors does not change in the presence of the steroid. As shown by electrophoresis (SDS–PAGE) and autoradiography, L-leucine is incorporated into adipocyte proteins as early as 20 min and progesterone increases this incorporation into five proteins. Leucine is a ketogenic amino acid that is also incorporated into lipids; progesterone depresses L-leucine incorporation into fatty acids by a glucose-dependent mechanism. These results suggest that the inhibitory effect of progesterone on glucose metabolism is related to an enhanced protein synthesis counterbalanced by decreased fatty acid synthesis.Key words: adipocytes, glucose metabolism, progesterone, protein synthesis, gel autoradiography.

Insulin action in pancreatic acini from streptozotocin-treated rats. I. Stimulation of protein synthesis

1981 ◽  
Vol 240 (1) ◽  
pp. G56-G62 ◽  
Author(s):  
M. Korc ◽  
Y. Iwamoto ◽  
H. Sankaran ◽  
J. A. Williams ◽  
I. D. Goldfine
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Cell Concentration ◽  
Enzyme Synthesis ◽  
Detectable Effect ◽  
Leucine Incorporation ◽  
Maximal Effect ◽  
Pancreatic Acini ◽  
Pancreatic Exocrine ◽  
Stimulation Of

Pancreatic acini were prepared from rats rendered diabetic with streptozotocin. In this tissue, insulin stimulated [3H]leucine incorporation into protein. The full effects of insulin on this function were not immediate but increased linearly with time for up to 2 h of incubation. Insulin had a detectable effect on l eucine incorporation at 50 pM, a half-maximal effect at 0.7 nM, and a maximal effect at 30 nM. Desdipeptide proinsulin was only 10% as potent as native insulin in stimulating [3H]leucine incorporation, whereas proinsulin and desoctapeptide insulin were only 1% as potent. Insulin also increased the incorporation of [3H]valine and [35S]methionine into protein but did not increase the influx of either [14C]cycloleucine or alpha-[3H]aminoisobutyric acid. These observations suggested that the increased incorporation of labeled amino acid into protein reflected stimulation of protein synthesis rather than stimulation of amino acid transport. Furthermore, insulin at 1.67 nM significantly increased the acinar cell concentration of amylase. The present findings are consistent therefore with the concept that insulin regulates pancreatic exocrine functions, including protein and enzyme synthesis.

Sign in / Sign up

Export Citation Format

Share Document