ACTH-induced c-myc proto-oncogene expression precedes antimitogenic effect during differentiation of fetal rat adrenocortical cells

1995 ◽  
Vol 145 (2) ◽  
pp. 379-385 ◽  
Author(s):  
P Heikkilä ◽  
J Arola ◽  
A Salmi ◽  
A I Kahri
Keyword(s):  
Mrna Expression ◽  
Inhibitory Effect ◽  
Zona Glomerulosa ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Synthesis Inhibitor ◽  
Adrenocortical Cells ◽  
Induced Expression ◽  
Inhibition Of Proliferation ◽  
Fetal Rat

Abstract The regulation of proto-oncogenes has been connected with proliferation and differentiation in various cell types. In the present study, the ACTH-induced expression of c-myc mRNA and proliferation of fetal rat adrenocortical cells have been studied. Low levels of c-myc mRNA were detected in undifferentiated zona glomerulosa-like cells. Stimulation with ACTH for 2 to 6 h transiently increased the c-myc mRNA levels. Both basal and ACTH-induced expression levels were increased by the protein synthesis inhibitor cycloheximide. Treatment with a protein kinase C (PKC) activator 12–0-tetradecanoyl phorbol-13-acetate mimicked the effect of ACTH, whereas c-myc mRNA levels decreased by inhibiting the PKC with H-7. ACTH inhibited proliferation of fetal rat adrenocortical cells during the first 24 h of stimulation. The inhibitory effect began from 6 h, reached its maximum at 12 h and slowly vanished at 24 h. Our data demonstrated that ACTH transiently increased c-myc mRNA expression. Adrenocortical c-myc expression was mediated via PKC. In contrast to previous reports, where c-myc expression precedes proliferation of various cells, ACTH-induced c-myc mRNA expression of cultured fetal rat adrenocortical cells was followed by inhibition of proliferation. Journal of Endocrinology (1995) 145, 379–385

Role of adenylate cyclase-cyclic AMP-dependent signal transduction in the ACTH-induced biphasic growth effect of rat adrenocortical cells in primary culture

1993 ◽  
Vol 139 (3) ◽  
pp. 451-NP ◽  
Author(s):  
J. Arola ◽  
P. Heikkilä ◽  
R. Voutilainen ◽  
A. I. Kahri
Keyword(s):  
Protein Synthesis ◽  
Cyclic Amp ◽  
Primary Culture ◽  
Zona Glomerulosa ◽  
Growth Effect ◽  
Protein Synthesis Inhibitor ◽  
Acth Stimulation ◽  
Synthesis Inhibitor ◽  
Adrenocortical Cells ◽  
Inhibition Of Proliferation

ABSTRACT ACTH has a biphasic effect on the proliferation of fetal rat adrenocortical cells in primary culture. Dramatic changes occurred during the first 72 h of ACTH stimulation, when incorporation of bromodeoxyuridine was used as an indicator of proliferation. The primary effect of ACTH was the inhibition of proliferation during the first 24 h, which was followed by an intense stimulatory phase during the third day of ACTH treatment. Cycloheximide (a protein synthesis inhibitor) prevented both the inhibitory and the stimulatory effects of ACTH, but did not affect the basal proliferation of unstimulated zona glomerulosa-like cells. Although adrenocortical cells stimulated with cyclic AMP (cAMP) derivatives, 8-bromo cAMP (8-Br cAMP) or dibutyryl cAMP ((Bu)2cAMP), differentiated morphologically into fasciculata-like cells, and secreted corticosterone and 18-OH-deoxycorticosterone, as did ACTH-stimulated cells, neither of the derivatives inhibited proliferation during the first 24 h of treatment. In contrast to ACTH, (Bu)2cAMP had a stimulatory effect on bromodeoxyuridine incorporation during the first 24 h of treatment. 8-Br cAMP did not change proliferation during the 24 h of treatment, but had a stimulatory effect after 72 h, which was not seen with (Bu)2cAMP. Thus, these results suggest that (1) differentiation, steroid hormone synthesis and the mitogenic effect of ACTH are transduced through the cAMP-mediated system, (2) the antimitogenic effect of ACTH is transduced via a cAMP-independent pathway and (3) both antimitogenic and mitogenic effects of ACTH are dependent on protein synthesis. Journal of Endocrinology (1993) 139, 451–461

Protein kinase C signal transduction pathway in ACTH-induced growth effect of rat adrenocortical cells in primary culture

1994 ◽  
Vol 141 (2) ◽  
pp. 285-293 ◽  
Author(s):  
J Arola ◽  
P Heikkilä ◽  
R Voutilainen ◽  
A I Kahri
Keyword(s):  
Protein Kinase C ◽  
Inhibitory Effect ◽  
Zona Glomerulosa ◽  
Growth Effect ◽  
Zona Fasciculata ◽  
Adrenocortical Cells ◽  
Steroid Secretion ◽  
Kinase C ◽  
Corticosterone Secretion ◽  
Fetal Rat

Abstract ACTH exerts a biphasic effect on the growth of fetal rat adrenocortical cells in primary culture when bromodeoxyuridine (BrdU) incorporation is used as an indicator of proliferation. The immediate inhibitory effect during the first 24 h of ACTH stimulation is not dependent on cyclic AMP (cAMP). Protein kinase C (PKC) inhibitors H-7 and staurosporine blocked this inhibitory effect of ACTH, whereas 12-0-tetradecanoyl phorbol-13-acetate (TPA; a PKC activator) mimicked the ACTH-induced antimitogenic effect. The stimulatory growth effect of ACTH appears after 72 h of treatment. A similar mitogenic effect is also achieved with cAMP derivative 8-bromo cAMP (8-Br cAMP). However, both ACTH- and 8-Br cAMP-induced proliferations could be reduced with H-7. ACTH-induced corticosterone secretion was inhibited 50% with H-7 after 24 h, but 8-Br cAMP-induced secretion was unaffected. However, if the treatments were continued for 72 h, H-7 no longer reduced the steroid secretions. Reduction (50–75%) of cholesterol side-chain cleavage enzyme (P450scc) mRNA expression was also noted with H-7 in ACTH-treated cultures after 6 and 24 h. In contrast, TPA doubled the corticosterone secretion induced by 8-Br cAMP, but did not further increase the ACTH-induced secretion after 24 h. TPA alone, however, was not able to induce steroid secretion or P450scc mRNA expression. The morphological differentiation of fetal rat adrenocortical cells with ACTH or 8-Br cAMP from zona glomerulosa-like cells into zona fasciculata-like cells was not disturbed by H-7 nor was it induced by TPA alone. These results therefore suggest that PKC- and cAMP-dependent signal transductions are involved in the ACTH-induced biphasic growth effect of fetal rat adrenocortical cells. PKC plays a role in the inhibitory growth effect, and both PKC and cAMP are involved in the stimulatory growth phase of ACTH. Both PKC and cAMP are also involved in the steroid secretion of zona glomerulosa-type cells, but differentiation into zona fasciculata-type cells and their steroid production is transduced through cAMP. Journal of Endocrinology (1994) 141, 285–293

Somatostatin-28 inhibitory action on somatolactin-α and -β gene expression in goldfish

2014 ◽  
Vol 307 (6) ◽  
pp. R755-R768 ◽  
Author(s):  
Quan Jiang ◽  
Anderson O. L. Wong
Keyword(s):  
Gene Expression ◽  
Mrna Expression ◽  
Primary Cultures ◽  
Inhibitory Effect ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Structural Identity ◽  
Rapid Amplification ◽  
Differential Coupling

Somatostain (SS) is known to inhibit growth hormone (GH) and prolactin (PRL) secretion. Somatolactin (SL) is a member of the GH/PRL family, but its regulation by goldfish brain somatostatin-28 (gbSS-28) has not been examined. To this end, the structural identity of goldfish SLα was established by 5′/3′-rapid amplification of cDNA ends. As revealed by in situ hybridization and immunohistochemical staining, the expression of SL isoforms was detected in pituitary cells located in the neurointermediate lobe (NIL). The transcripts of goldfish SS receptor 5a (Sst5a) but not Sst1b, Sst2, or Sst3a were detected in the goldfish NIL cells by RT-PCR. In goldfish pituitary cells, gbSS-28 not only had an inhibitory effect on basal SLα and SLβ mRNA levels but also could abolish insulin-like growth factor-stimulated SL gene expression. In primary cultures of goldfish NIL cells, gbSS-28 reduced forskolin-stimulated total cAMP production. With the use of a pharmacological approach, the adenylate cyclase (AC)/cAMP and phospholipase C (PLC)/inositol trisphosphate (IP3)/protein kinase C (PKC) cascades were shown to be involved in gbSS-28-inhibited SLα mRNA expression. Similar postreceptor signaling cascades were also observed for gbSS-28-reduced SLβ mRNA expression, except that PKC coupling to PLC was not involved. These results provide evidence that gbSS-28 can inhibit SLα and SLβ gene expression at the goldfish pituitary level via Sst5 through differential coupling of AC/cAMP and PLC/IP3/PKC cascades.

scholarly journals BMP-4 inhibits follicle-stimulating hormone secretion in ewe pituitary

2005 ◽  
Vol 186 (1) ◽  
pp. 109-121 ◽  
Author(s):  
M-O Faure ◽  
L Nicol ◽  
S Fabre ◽  
J Fontaine ◽  
N Mohoric ◽  
...  
Keyword(s):  
Growth Factor ◽  
Mrna Expression ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Hormone Secretion ◽  
Inhibitory Effect ◽  
Type I ◽  
Mrna Levels ◽  
Dependent Manner

Activins and inhibins, members of the transforming growth factor-beta family are able to stimulate and inhibit, respectively, FSH synthesis and release. Other members of this superfamily, the bone morphogenetic proteins (BMPs), may also affect FSH synthesis in the mouse. The aim of this work was to determine whether BMPs are expressed in the ovine pituitary and whether they play a role in the regulation of FSH release. The mRNAs encoding BMP-2, BMP-4, BMP-7 and the oocyte-derived growth factor, growth differentiation factor (GDF)-9 were detected in the pituitaries of cyclic ewes by reverse-transcriptase PCR, as well as the mRNAs encoding the BMP type I receptors, BMPR-IA (activin-receptor-like kinase (ALK)-3) and BMPR-IB (ALK-6), and type II receptors (BMPR-II). Immunolabeling of pituitary sections revealed the presence of BMPR-IA (ALK-3) and BMPR-II in gonadotrope cells. To investigate the potential effects of BMPs on FSH secretion, ewe pituitary cell cultures were treated with BMP-4 (10−11 M to 10−9 M) for 48 h. Interestingly, FSH release was decreased in a dose-dependent manner. At 10−9 M BMP-4 both FSH concentration and FSHβ mRNA expression were reduced by 40% of control values. In contrast, there was no inhibitory effect on either LH or LHβ mRNA expression. A similar result was found with BMP-6. BMP-4 triggered the phosphorylation of Smad1, suggesting that the effect of BMP-4 on FSH secretion is due to the activation of the BMPs signaling pathway. Furthermore, BMP-4 blocked the stimulatory effect of activin on both FSH release and FSHβ mRNA and amplified the suppression of FSH release and FSHβ mRNA levels induced by 17β-estradiol. These results indicate that a functional BMP system operates within the sheep pituitary, at least in vitro, to decrease FSH release and to modulate the effect of activin.

scholarly journals Characterization of murine bone marrow and spleen-derived stromal cells: analysis of leukocyte marker and growth factor mRNA transcript levels

Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 303-311
Author(s):  
JM Gimble ◽  
C Pietrangeli ◽  
A Henley ◽  
MA Dorheim ◽  
J Silver ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Stromal Cells ◽  
Interleukin 6 ◽  
Transforming Growth Factor ◽  
Immunoglobulin Superfamily ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Synthesis Inhibitor

Stromal cells are believed to regulate lympho-hematopoiesis through direct cell-cell interactions and the release of growth factors. Many questions remain, however, about their lineage derivation and functional heterogeneity. We previously prepared a panel of stromal cell lines from murine spleen and bone marrow and characterized them based on their ability to support lymphocyte growth in long-term cultures. These cells are now compared with respect to their expression of various immunoglobulin superfamily and cytokine genes by Northern blot analysis. These results indicate that although stromal cells appear to be mesodermal in origin, they are not closely related developmentally to the hematopoietic progenitor cells they support. The potential production of at least six cytokines was demonstrated. All clones constitutively expressed mRNA for macrophage colony stimulating factor, interleukin-6, transforming growth factor beta and neuroleukin. The most potent lymphocyte supporting clones also made interleukin 7 constitutively. Previous findings had suggested that these clones responded to exogenous stimuli and this has now been demonstrated in terms of induced expression of IL-6 and G/M-CSF mRNA. Interleukin 6 mRNA levels were markedly upregulated by exposure of cells to LPS, TNF, IL-1, IL-6, IL-7, and EGF. G/M-CSF mRNA levels were “superinduced” by the combination of LPS and cycloheximide, a protein synthesis inhibitor. These responses are similar to ones documented by investigators working with endothelial cells and fibroblasts. Together, these data suggest that stromal cells are a multifunctional component of the lymphopoietic microenvironment and may be active participants in a complex, cytokine-mediated regulatory network.

scholarly journals Chinese hamster cells can be reversibly blocked before mitosis with the protein synthesis inhibitor, emetine

1983 ◽  
Vol 59 (1) ◽  
pp. 257-268
Author(s):  
J.T. Westwood ◽  
E.B. Wagenaar
Keyword(s):  
Protein Synthesis ◽  
Mitotic Index ◽  
Chinese Hamster ◽  
Inhibitory Effect ◽  
Eukaryotic Cells ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Chinese Hamster Cells ◽  
Initial Concentration ◽  
G2 Phase

The inhibition of protein synthesis in eukaryotic cells will prevent them from entering mitosis. Emetine inhibits peptide elongation. When it was added to asynchronous populations of Chinese hamster ovary (CHO) cells, the mitotic index decreased sharply 30 to 40 min later. It was found that the inhibitory effect of emetine could be reversed when it was removed and the reversibility was dependent on both the initial concentration of emetine and the pH of the medium. Cell populations that were blocked by emetine for up to 2h showed a four- to fivefold increase in mitotic index approximately 1 h after the emetine was removed. These results indicate that there is a point or period in G2 phase at which critical ‘mitotic proteins’ are being synthesized, and if their synthesis is interrupted cells will fail to enter mitosis.

High affinity promoter binding of STOP1 is essential for the early aluminum-inducible expression of novel Al resistance genes GDH1 and GDH2 in Arabidopsis

2021 ◽  
Author(s):  
Mutsutomo Tokizawa ◽  
Takuo Enomoto ◽  
Hiroki Ito ◽  
Liujie Wu ◽  
Yuriko Kobayashi ◽  
...  
Keyword(s):  
Binding Site ◽  
Resistance Genes ◽  
Translational Regulation ◽  
Molecular Mechanisms ◽  
Aluminum Toxicity ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Induced Expression ◽  
Aluminum Resistance ◽  
High Affinity

Abstract Malate-efflux from roots, which is regulated by the transcription factor STOP1 (SENSITIVE-TO-PROTON-RHIZOTOXICITY1), which mediates aluminum-induced expression of ALUMINUM-ACTIVATED-MALATE-TRANSPORTER1 (AtALMT1), is critical for aluminum-resistance in Arabidopsis thaliana. Several studies showed that root AtALMT1 expression is rapidly observed in response to aluminum (within 1-hour), this early induction is an important mechanism to immediately protect roots from aluminum-toxicity. Additionally, identifying the molecular mechanisms that underlie rapid aluminum-resistance responses should lead to a better understanding of plant aluminum-sensing and -signal transduction mechanisms. In this study, histochemical analyses using GFP-tagged STOP1 proteins showed that STOP1 proteins were accumulated in the nucleus soon after aluminum-treatment. The rapid aluminum-induced STOP1-nuclear localization and AtALMT1-induction were observed in the presence of the protein synthesis inhibitor, suggesting that post-translational regulation is involved in these events. STOP1 also regulated rapid aluminum-induced expression for other genes that carry a functional/high-affinity STOP1-binding site in their promoter, including STOP2, GLUTAMATE-DEHYDROGENASE1 and 2 (GDH1 and 2), but not for Al resistance genes which have no functional STOP1-binding site such as ALUMINUM-SENSITIVE3, suggesting that the binding of STOP1 in the promoter is essential for the early induction. Finally, we report that GDH1 and 2 which are the target of STOP1 are novel aluminum-resistance genes in Arabidopsis.

Transcriptional and posttranscriptional regulation of CSF-1 gene expression in human monocytes

1988 ◽  
Vol 8 (9) ◽  
pp. 3951-3954
Author(s):  
J Horiguchi ◽  
E Sariban ◽  
D Kufe
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Gene Transcription ◽  
Posttranscriptional Regulation ◽  
Drug Exposure ◽  
Actinomycin D ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Human Monocytes ◽  
Synthesis Inhibitor

Regulation of CSF-1 gene expression was investigated in human monocytes. CSF-1 transcripts were at low or undetectable levels in resting monocytes. However, in monocytes treated with 12-O-tetradecanoylphorbol-13-acetate (TPA), CSF-1 mRNA was increased by 3 h and reached maximal levels by 12 h of drug exposure. When nuclear run-on assays were used, CSF-1 gene transcription was also at low or undetectable levels in resting monocytes but was activated after TPA exposure. TPA-treated monocytes exposed to actinomycin D further demonstrated that the half-life of the CSF-1 mRNA is 0.9 h. The results also demonstrated that the protein synthesis inhibitor, cycloheximide (CHX), increases CSF-1 mRNA levels in both resting and TPA-treated monocytes. These effects of CHX occurred in the absence of detectable increases in CSF-1 gene transcription. Moreover, treatment of monocytes with CHX and actinomycin D demonstrated that inhibition of protein synthesis is associated with stabilization of the CSF-1 transcript. Taken together, these findings indicated that CSF-1 gene expression is controlled at both transcriptional and posttranscriptional levels in human monocytes.

Regulation of Heme Oxygenase-1 Gene Expression by Anoxia and Reoxygenation in Primary Rat Hepatocyte Cultures

2003 ◽  
Vol 228 (5) ◽  
pp. 584-589 ◽  
Author(s):  
Andreas Ohlmann ◽  
Susanne Giffhorn-Katz ◽  
Ivonne Becker ◽  
Norbert Katz ◽  
Stephan Immenschuh
Keyword(s):  
Gene Expression ◽  
Mrna Expression ◽  
Heme Oxygenase ◽  
Heme Oxygenase 1 ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Rat Hepatocyte ◽  
Hsp70 Mrna ◽  
Hepatocyte Cultures ◽  
Antioxidant Agents

Heme oxygenase (HO) catalyzes the rate-limiting enzymatic step of heme degradation and regulates the cellular heme content. Gene expression of the inducible isoform of HO, HO-1, is upregulated in response to various oxidative stress stimuli. To investigate the regulatory role of anoxia and reoxygenation (A/R) on hepatic HO-1 gene expression, primary cultures of rat hepatocytes were exposed after an anoxia of 4 hr to normal oxygen tension for various lengths of time. For comparison, gene expression of the noninducible HO isoform, HO-2, and that of the heat-shock protein 70 (HSP70) were determined. During reoxygenation, a marked increase of HO-1 and HSP70 steady-state mRNA levels was observed, whereas no alteration of HO-2 mRNA levels occurred. Corresponding to HO-1 mRNA, an increase of HO-1 protein expression was determined by Western blot analysis. The anoxia-dependent induction of HO-1 was prevented by pretreatment with the transcription inhibitor, actinomycin D, but not by the protein synthesis inhibitor, cycloheximide, suggesting a transcriptional regulatory mechanism. After exposure of hepatocytes to anoxia, the relative levels of oxidized glutathione increased within the first 40 min of reoxygenation. Pretreament of cell cultures with the antioxidant agents, β-carotene and allopurinol, before exposure to A/R led to a marked decrease of HO-1 and HSP70 mRNA expression during reoxygenation. An even more pronounced reduction of mRNA expression was observed after exposure to desferrioxamine. Taken together, the data demonstrate that HO-1 gene expression in rat hepatocyte cultures after A/R is upregulated by a transcriptional mechanism that may be, in part, mediated via the generation of ROS and the glutathione system.

scholarly journals Regulation of histone mRNA in the unperturbed cell cycle: evidence suggesting control at two posttranscriptional steps.

1991 ◽  
Vol 11 (5) ◽  
pp. 2416-2424 ◽  
Author(s):  
M E Harris ◽  
R Böhni ◽  
M H Schneiderman ◽  
L Ramamurthy ◽  
D Schümperli ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Half Life ◽  
S Phase ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Histone Mrna ◽  
Synthesis Inhibitor ◽  
Processing Efficiency ◽  
Histone 3 ◽  
Cycle Regulation

The levels of histone mRNA increase 35-fold as selectively detached mitotic CHO cells progress from mitosis through G1 and into S phase. Using an exogenous gene with a histone 3' end which is not sensitive to transcriptional or half-life regulation, we show that 3' processing is regulated as cells progress from G1 to S phase. The half-life of histone mRNA is similar in G1- and S-phase cells, as measured after inhibition of transcription by actinomycin D (dactinomycin) or indirectly after stabilization by the protein synthesis inhibitor cycloheximide. Taken together, these results suggest that the change in histone mRNA levels between G1- and S-phase cells must be due to an increase in the rate of biosynthesis, a combination of changes in transcription rate and processing efficiency. In G2 phase, there is a rapid 35-fold decrease in the histone mRNA concentration which our results suggest is due primarily to an altered stability of histone mRNA. These results are consistent with a model for cell cycle regulation of histone mRNA levels in which the effects on both RNA 3' processing and transcription, rather than alterations in mRNA stability, are the major mechanisms by which low histone mRNA levels are maintained during G1.

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