scholarly journals The effect of lutropin on specific protein synthesis in tumour Leydig cells and in Leydig cells from immature rats

1978 ◽  
Vol 172 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Felix H. A. Janszen ◽  
Brian A. Cooke ◽  
Maria J. A. Van Driel ◽  
Henk J. Van Der Molen
Keyword(s):  
Protein Synthesis ◽  
Leydig Cells ◽  
Sodium Dodecyl ◽  
Specific Protein ◽  
Side Chain ◽  
Chain Cleavage ◽  
Immature Rats ◽  
Cleavage Enzyme ◽  
Induced Proteins ◽  
Stimulation Of

The amount of35S incorporated into the various proteins after separation by electrophoresis on sodium dodecyl sulphate/polyacrylamide gels was used as an estimate of their synthesis in the Leydig cells. Increased synthesis of proteins with apparent mol.wts. 27000 and 29000 was observed 3h after addition of lutropin to tumour Leydig cells. Incubation of Leydig cells from immature rats with lutropin (100ng/ml) for 2h or longer resulted in increased synthesis of proteins with apparent mol.wts. 11000, 21000, 27000 and 29000. At higher concentrations (≥100ng/ml) of lutropin there was a decrease in the synthesis of a protein with apparent mol.wt. 13000. The amount of lutropin required for the stimulation of protein synthesis in both types of Leydig cells was similar to that needed for stimulation of steroidogenesis. Lutropin-stimulated specific protein synthesis was not due to increased concentrations of testosterone, however, because (1) addition of testosterone to the cells had no effect on the synthesis of the proteins, and (2) inhibition of steroidogenesis with elipten phosphate (an inhibitor of the cholesterol side-chain-cleavage enzyme complex) did not abolish the effect of lutropin. The stimulation of specific protein synthesis was also not due to contaminating follitropin in the lutropin preparation. Addition of actinomycin D to the cells at the start of the incubation prevented the effect of lutropin on specific protein synthesis, indicating that mRNA synthesis may be needed for this effect of lutropin. Incubation of the cells with cycloheximide for 30min after labelling of the proteins did not result in a detectable decrease in the amounts of the lutropin-induced proteins, indicating that their half-life is longer than 30min.

scholarly journals Stimulation of cholesterol side-chain cleavage by a luteinizing-hormone-releasing hormone (luliberin) agonist (ICI 118630) in rat Leydig cells

1983 ◽  
Vol 216 (3) ◽  
pp. 747-752 ◽  
Author(s):  
M H F Sullivan ◽  
B A Cooke
Keyword(s):  
Luteinizing Hormone ◽  
Leydig Cells ◽  
Side Chain ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Cleavage Enzyme ◽  
Cytochrome P 450 ◽  
Stimulation Of

The action of a luliberin (luteinizing-hormone-releasing hormone) agonist (ICI 118630) and lutropin (luteinizing hormone) on the activity of the cytochrome P-450 cholesterol side-chain cleavage enzyme in rat Leydig cells has been investigated. This has been carried out by studying the metabolism of exogenous (22R)-22- and 25-hydroxycholesterol to testosterone. It was found that both hydroxycholesterols increased testosterone production to higher levels than achieved by lutropin alone. Addition of luliberin agonist but not lutropin was found to increase further the metabolism of the hydroxycholesterol to testosterone; this occurred in the presence of saturating and subsaturating levels of the hydroxycholesterols. This effect of luliberin agonist was potentiated in the presence of lutropin. The protein synthesis inhibitor, cycloheximide, inhibited the luliberin agonist-induced stimulation of the hydroxycholesterol metabolism. At low calcium levels (1.1 microM), testosterone production was increased by addition of (22R)-22-hydroxycholesterol but the luliberin agonist effect was negated. The calmodulin inhibitor trifluoperazine inhibited (22R)-22-hydroxycholesterol-stimulated steroidogenesis and negated the luliberin agonist effect. These results indicate that luliberin agonist specifically increases the synthesis of the cytochrome P-450 cholesterol side-chain cleavage enzyme in rat testis Leydig cells.

scholarly journals Evaluation of relative roles of LH and FSH in regulation of differentiation of Leydig cells using an ethane 1,2-dimethylsulfonate-treated adult rat model

2003 ◽  
Vol 176 (1) ◽  
pp. 151-161 ◽  
Author(s):  
V Sriraman ◽  
MR Sairam ◽  
AJ Rao
Keyword(s):  
Leydig Cells ◽  
Serum Testosterone ◽  
Side Chain ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Lh Receptor ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Cleavage Enzyme

The relative role of LH and FSH in regulation of differentiation of Leydig cells was assessed using an ethane 1,2-dimethylsulfonate (EDS)-treated rat model in which endogenous LH or FSH was neutralized from day 3 to day 22 following EDS treatment. Serum testosterone and the in vitro response of the purified Leydig cells to human chorionic gonadotropin (hCG) was monitored. In addition RNA was isolated from the Leydig cells to monitor the steady-state mRNA levels by RT-PCR for 17alpha-hydroxylase, side chain cleavage enzyme, steroidogenic acute regulatory protein (StAR), LH receptor, estrogen receptor (ER-alpha) and cyclophilin (internal control). Serum testosterone was undetected and the isolated Leydig cells secreted negligible amount of testosterone on stimulation with hCG in the group of rats that were treated with LH antiserum following EDS treatment. RT-PCR analysis revealed the absence of message for cholesterol side chain cleavage enzyme and 17alpha-hydroxylase although ER-alpha and LH receptor mRNA could be detected, indicating the presence of undifferentiated precursor Leydig cells. In contrast, the effects following deprival of endogenous FSH were not as drastic as seen following LH neutralization. Deprival of endogenous FSH in EDS-treated rats led to a significant decrease in serum testosterone and in vitro response to hCG by the Leydig cells. Also, there was a significant decrease in the steady-state mRNA levels of 17alpha-hydroxylase, cholesterol side chain cleavage enzyme, LH receptor and StAR as assessed by a semiquantitative RT-PCR. These results establish that while LH is obligatory for the functional differentiation of Leydig cells, repopulation of precursor Leydig cells is independent of LH, and also unequivocally establish an important role for FSH in regulation of Leydig cell function.

scholarly journals Specific protein synthesis in isolated rat testis leydig cells. Influence of luteinizing hormone and cycloheximide

1977 ◽  
Vol 162 (2) ◽  
pp. 341-346 ◽  
Author(s):  
F H A Janszen ◽  
B A Cooke ◽  
H J van der Molen
Keyword(s):  
Protein Synthesis ◽  
Luteinizing Hormone ◽  
Leydig Cell ◽  
Half Life ◽  
Leydig Cells ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Protein Band ◽  
Specific Protein ◽  
Rat Testis

The effect of luteinizing hormone (luteotropin) and cycloheximide on specific protein synthesis in rat testis Leydig cells has been investigated. Proteins were labelled with either I114C]leucine, [3H]leucine or [35S]methionine during incubation with Leydig-cell suspensions in vitro. Total protein was extracted from the cells and separated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. No detectable increase in the synthesis of specific proteins could be observed after incubation of Leydig cells with luteinizing hormone for up to 1 h. However, after a 2h incubation period, an increase in [35S]methionine incorporation was observed in a protein with an apparent mol.wt. of 21000 (referred to as ‘protein 21’). When, after labelling of this protein with [35S]-methionine, Leydig cells were incubated for another 30min with cycloheximide, no decrease in radioactivity of this protein band was observed, indicating that it does not have a short half-life. However, another protein band was detected, which after incubation with cycloheximide disappeared rapidly, the reaction following first-order kinetics, with a half-life of about 11 min. This protein, with an apparent mol.wt. of 33000 (referred to as “protein 33”), was found to be located in the particulate fraction of the Leydig cell, and could not be demonstrated in other rat testis-cell types or blood cells. No effect of luteinizing hormone on molecular weight, subcellular localization or half-life of protein 33 was observed. A possible role for protein 33 and protein 21 in the mechanism of action of luteinizing hormone on testosterone production of Leydig cells is discussed.

Notch signalling regulates steroidogenesis in mouse ovarian granulosa cells

2019 ◽  
Vol 31 (6) ◽  
pp. 1091 ◽  
Author(s):  
Yishu Wang ◽  
Enhang Lu ◽  
Riqiang Bao ◽  
Ping Xu ◽  
Fen Feng ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Granulosa Cells ◽  
Notch Signalling ◽  
Side Chain ◽  
Notch Signalling Pathway ◽  
Steroidogenic Factor 1 ◽  
Ovarian Granulosa Cells ◽  
Chain Cleavage ◽  
Cleavage Enzyme ◽  
Stimulation Of

The Notch signalling pathway in the mammalian ovary regulates granulosa cell proliferation. However, the effects of Notch signalling on steroidogenesis are unclear. In this study we cultured mouse ovarian granulosa cells from preantral follicles invitro and observed the effect of Notch signalling on steroidogenesis through overexpression, knockdown and inhibition of Notch signalling. Activation of Notch signalling decreased progesterone and oestrogen secretion. In contrast, inhibition of Notch signalling increased the production of progesterone and oestrogen. Expression of the genes for steroidogenic-related enzymes, including 3β-hydroxysteroid dehydrogenase, p450 cholesterol side-chain cleavage enzyme and aromatase, was repressed after stimulation of Notch signalling. The expression of upstream transcription factors, including steroidogenic factor 1 (SF1), Wilms’ tumour 1 (Wt1), GATA-binding protein 4 (Gata4) and Gata6, was also inhibited after stimulation of Notch signalling. Production of interleukin (IL)-6 was positively correlated with Notch signalling and negatively correlated with the expression of these transcription factors and enzymes. In conclusion, Notch signalling regulated progesterone and oestrogen secretion by affecting the expression of upstream transcription factors SF1, Wt1, Gata4 and Gata6, as well as downstream steroidogenic-related enzymes. IL-6, which may be regulated directly by Notch signalling, may contribute to this process. Our findings add to the understanding of the diverse functions of Notch signalling in the mammalian ovary.

scholarly journals Activation of a Neural Brain-Testicular Pathway Rapidly Lowers Leydig Cell Levels of the Steroidogenic Acute Regulatory Protein and the Peripheral-Type Benzodiazepine Receptor while Increasing Levels of Neuronal Nitric Oxide Synthase

Endocrinology ◽  
2006 ◽  
Vol 147 (1) ◽  
pp. 624-633 ◽  
Author(s):  
Melissa Herman ◽  
Catherine Rivier
Keyword(s):  
Nitric Oxide ◽  
Leydig Cells ◽  
Neuronal Nitric Oxide Synthase ◽  
Benzodiazepine Receptor ◽  
Side Chain ◽  
Chain Cleavage ◽  
Cleavage Enzyme ◽  
Peripheral Type ◽  
Steroidogenic Acute Regulatory ◽  
Oxide Synthase

Activation of a neural brain-testicular pathway by the intracerebroventricular injection of the β-adrenergic agonist isoproterenol (ISO), the hypothalamic peptide corticotropin-releasing factor (CRF), or alcohol (EtOH) rapidly decreases the testosterone (T) response to human chorionic gonadotropin. To elucidate the intratesticular mechanisms responsible for this phenomenon, we investigated the influence of intracerebroventricular-injected ISO, CRF, or EtOH on levels of the steroidogenic acute regulatory (StAR) protein, the peripheral-type benzodiazepine receptor (PBR), and the cytochrome P450 side-chain cleavage enzyme in semipurified Leydig cells. ISO (10 μg), CRF (5 μg), or EtOH (5 μl of 200 proof, a dose that does not induce neuronal damage nor leaks to the periphery) rapidly decreased StAR and PBR but not cytochrome P450 side-chain cleavage enzyme protein levels. Levels of the variant of the neuronal nitric oxide synthase (nNOS) that is restricted to Leydig cells, TnNOS, significantly increased in response to ISO, CRF, and EtOH over the time course of altered StAR/PBR concentrations. However, pretreatment of the rats with Nwnitro-arginine methylester, which blocked ISO-induced increases in TnNOS, neither restored the T response to human chorionic gonadotropin nor prevented the decreases in StAR and PBR. These results provide evidence of concomitant changes in Leydig cell StAR and PBR levels in live rats. They also indicate that activation of a neural brain-testicular pathway rapidly decreases concentrations of these steroidogenic proteins while up-regulating testicular NO production. However, additional studies are necessary to elucidate the functional role played by this gas in our model.

scholarly journals Stimulation of the P-450 side chain cleavage enzyme (CYP11A1) promoter through ras- and Ets-2-signaling pathways.

1996 ◽  
Vol 10 (9) ◽  
pp. 1084-1094
Author(s):  
R G Pestell ◽  
C Albanese ◽  
G Watanabe ◽  
R J Lee ◽  
P Lastowiecki ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Side Chain ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Cleavage Enzyme ◽  
Stimulation Of

scholarly journals Calmidazolium is a potent stimulator of steroidogenesis via mechanisms not involving cyclic AMP, calcium or protein synthesis

1992 ◽  
Vol 281 (1) ◽  
pp. 291-296 ◽  
Author(s):  
M S K Choi ◽  
B A Cooke
Keyword(s):  
Protein Synthesis ◽  
Cyclic Amp ◽  
Leydig Cells ◽  
Dose Range ◽  
Protein Translation ◽  
Side Chain ◽  
Dibutyryl Cyclic Amp ◽  
Adrenocortical Cells ◽  
Potent Stimulator ◽  
Chain Cleavage

This study reports an unexpected effect of calmidazolium on steroidogenesis. In contrast with previous work, which established that calmidazolium inhibits hormone-stimulated testosterone production in rat Leydig cells, the present study demonstrates that this compound is a potent stimulator of steroidogenesis when added by itself; this stimulation (approx. 10-fold in a 2 h incubation), was obtained over a narrow dose range (e.g.1-10 microM) in mouse and rat Leydig cells and in rat adrenocortical cells. The same concentrations of calmidazolium decreased basal cyclic AMP to undetectable levels in rat Leydig cells. Also, cyclic AMP stimulated with luteinizing hormone (LH), cholera toxin and forskolin was inhibited by calmidazolium (ED50 2 microM). In contrast with the actions of LH and cyclic AMP analogues on steroidogenesis, the effect of calmidazolium was not inhibited by removal of extracellular Ca2+, or by the addition of La3+ (a Ca(2+)-entry blocker), or the addition of cycloheximide (an inhibitor of protein translation). However, like dibutyryl cyclic AMP, calmidazolium-stimulated steroidogenesis was inhibited by aminoglutethimide, an inhibitor of cholesterol side-chain cleavage. Another calmodulin inhibitor, trifluoperazine, did not stimulate steroidogenesis. It is concluded that calmidazolium has a similar effect on steroidogenesis to LH, but by-passes the requirements for cyclic AMP, Ca2+, and protein synthesis. Calmidazolium is therefore a potentially important probe for elucidating the mechansims of control of steroidogenesis.

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