scholarly journals Stress-induced regulation of steroidogenic acute regulatory protein expression in head kidney of Gilthead seabream (Sparus aurata)

2007 ◽  
Vol 196 (2) ◽  
pp. 313-322 ◽  
Author(s):  
Juan Castillo ◽  
Barbara Castellana ◽  
Laura Acerete ◽  
Josep V Planas ◽  
Frederick W Goetz ◽  
...  
Keyword(s):  
Acute Stress ◽  
Sparus Aurata ◽  
Regulatory Protein ◽  
Head Kidney ◽  
Steroidogenic Acute Regulatory Protein ◽  
Gilthead Seabream ◽  
Mrna Levels ◽  
High Sequence Identity ◽  
Cortisol Levels ◽  
Steroidogenic Acute Regulatory

Steroidogenic acute regulatory protein (StAR) transfers cholesterol over the inner mitochondrial membrane. In mammals, StAR controls this rate-limiting step of steroidogenesis, but its expression and regulation has not been well explored in fish. The present work investigates StAR mRNA expression in the head kidney of the gilthead seabream (Sparus aurata) under different stressors. We have cloned the StAR cDNA (1461 bp) in seabream (accession number EF640987), which has an open reading frame of 861 nucleotides encoding a polypeptide of 286 aa, and displays high sequence identity with StAR of other fish and mammalian counterparts. Seabream StAR transcripts were found to be expressed exclusively in head kidneys and gonads. In fish under acute stress (chased with a net), plasma cortisol levels peaked within 1 h, were still high after 6 h, and decreased after 16 h, although no increases in head kidney StAR expression were observed at any time post-stressor. Fish under chronic high-density stress showed cortisol levels 90-fold higher than controls and StAR mRNA levels increased threefold. Lipopolysaccharide (LPS) injection increased head kidney StAR mRNA levels after 6 h, reached a maximum at 12 h, and decreased until 72 h. When the head kidney cells were incubated in vitro and treated with ACTH or LPS, ACTH induced an increase in StAR expression as expected, but LPS induced a reduction in StAR expression. In conclusion, StAR expression in seabream head kidneys is highly regulated by different stressors.

scholarly journals Regulation by Adrenocorticotropin (ACTH), Angiotensin II, Transforming Growth Factor-β, and Insulin-Like Growth Factor I of Bovine Adrenal Cell Steroidogenic Capacity and Expression of ACTH Receptor, Steroidogenic Acute Regulatory Protein, Cytochrome P450c17, and 3β-Hydroxysteroid Dehydrogenase*

Endocrinology ◽  
2000 ◽  
Vol 141 (5) ◽  
pp. 1599-1607 ◽  
Author(s):  
Christine Le Roy ◽  
J. Yuan Li ◽  
Douglas M. Stocco ◽  
Dominique Langlois ◽  
José M. Saez
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Regulatory Protein ◽  
Hydroxysteroid Dehydrogenase ◽  
Steroidogenic Acute Regulatory Protein ◽  
Mrna Levels ◽  
Factor I ◽  
Acth Receptor ◽  
Igf I ◽  
Steroidogenic Acute Regulatory

Abstract The purpose of this study was to evaluate the time-course effect of a 36-h treatment with ACTH (10−8m), transforming growth factor-β1 (TGFβ1; 10−10m), angiotensin II (AngII; 10−7m), and insulin-like growth factor I (IGF-I; 10−8m) on the steroidogenic capacity of bovine adrenocortical cells (BAC) and on messenger RNA (mRNA) levels of ACTH receptor, cytochrome P450c17, 3β-hydroxysteroid dehydrogenase (3βHSD), steroidogenic acute regulatory protein (StAR), and StAR protein. ACTH and IGF-I enhanced, in a time-dependent manner, the acute 2-h ACTH-induced cortisol production, whereas TGFβ1 and AngII markedly reduced it. ACTH, IGF-I, and AngII increased ACTH receptor mRNA, but the opposite was observed after TGFβ1 treatment. ACTH and IGF-I increased P450c17 and 3βHSD mRNAs, whereas AngII and TGFβ1 had the opposite effects. However, the effects of the four peptides on ACTH-induced cortisol production appeared before any significant alterations of the mRNA levels occurred. The most marked and rapid effect of the four peptides was on StAR mRNA. The stimulatory effect of ACTH was seen within 1.5 h, peaked at 4–6 h, and declined thereafter, but at the end of the 36-h pretreatment, the levels of StAR mRNA and protein were higher than those in control cells. IGF-I also enhanced StAR mRNA levels within 1.5 h, and these levels remained fairly constant. The effects of AngII on StAR mRNA expression were biphasic, with a peak within 1.5–3 h, followed by a rapid decline to almost undetectable levels of both mRNA and protein. TGFβ1 had no significant effect during the first 3 h, but thereafter StAR mRNA declined, and at the end of the experiment the StAR mRNA and protein were almost undetectable. Similar results were observed when cells were treated with ACTH plus TGFβ1. A 2-h acute ACTH stimulation at the end of the 36-h pretreatment caused a higher increase in StAR mRNA and protein in ACTH- or IGF-I-pretreated cells than in control cells, which, in turn, had higher levels than cells pretreated with TGFβ1, ACTH plus TGFβ1, or AngII. These results and the fact that the stimulatory (IGF-I) or inhibitory (AngII and TGFβ1) effects on ACTH-induced cortisol production were more pronounced than those on the ability of cells to transform pregnenolone into cortisol strongly suggest that regulation of StAR expression is one of the main factors, but not the only one, involved in the positive (IGF-I) or negative (TGFβ1 and AngII) regulation of BAC for ACTH steroidogenic responsiveness. A high correlation between steady state mRNA level and acute ACTH-induced cortisol production favors this conclusion.

scholarly journals Salt-Inducible Kinase Is Involved in the ACTH/cAMP-Dependent Protein Kinase Signaling in Y1 Mouse Adrenocortical Tumor Cells

2001 ◽  
Vol 15 (8) ◽  
pp. 1264-1276 ◽  
Author(s):  
Xing-zi Lin ◽  
Hiroshi Takemori ◽  
Yoshiko Katoh ◽  
Junko Doi ◽  
Nanao Horike ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Promoter Activity ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Side Chain ◽  
Mrna Levels ◽  
Steroidogenic Factor 1 ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Steroidogenic Acute Regulatory

Abstract The involvement of salt-inducible kinase, a recently cloned protein serine/threonine kinase, in adrenal steroidogenesis was investigated. When Y1 mouse adrenocortical tumor cells were stimulated by ACTH, the cellular content of salt-inducible kinase mRNA, protein, and enzyme activity changed rapidly. Its level reached the highest point in 1–2 h and returned to the initial level after 8 h. The mRNA levels of cholesterol side-chain cleavage cytochrome P450 and steroidogenic acute regulatory protein, on the other hand, began to rise after a few hours, reaching the highest levels after 8 h. The salt-inducible kinase mRNA level in ACTH-, forskolin-, or 8-bromo-cAMP-treated Kin-7 cells, mutant Y1 with less cAMP-dependent PKA activity, remained low. However, Kin-7 cells, when transfected with a PKA expression vector, expressed salt-inducible kinase mRNA. Y1 cells that overexpressed salt-inducible kinase were isolated, and the mRNA levels of steroidogenic genes in these cells were compared with those in the parent Y1. The level of cholesterol side-chain cleavage cytochrome P450 mRNA in the salt-inducible kinase-overexpressing cells was markedly low compared with that in the parent, while the levels of Ad4BP/steroidogenic factor-1-, ACTH receptor-, and steroidogenic acute regulatory protein-mRNAs in the former were similar to those in the latter. The ACTH-dependent expression of cholesterol side-chain cleavage cytochrome P450- and steroidogenic acute regulatory protein-mRNAs in the salt-inducible kinase-overexpressing cells was significantly repressed. The promoter activity of the cholesterol side-chain cleavage cytochrome P450 gene was assayed by using Y1 cells transfected with a human cholesterol side-chain cleavage cytochrome P450 promoter-linked reporter gene. Addition of forskolin to the culture medium enhanced the cholesterol side-chain cleavage cytochrome P450 promoter activity, but the forskolin-dependently activated promoter activity was inhibited when the cells were transfected with a salt-inducible kinase expression vector. This inhibition did not occur when the cells were transfected with a salt-inducible kinase (K56M) vector that encoded an inactive kinase. The salt-inducible kinase’s inhibitory effect was also observed when nonsteroidogenic, nonAd4BP/steroidogenic factor-1 -expressing, NIH3T3 cells were used for the promoter assays. These results suggested that salt-inducible kinase might play an important role(s) in the cAMP-dependent, but Ad4BP/steroidogenic factor-1-independent, gene expression of cholesterol side-chain cleavage cytochrome P450 in adrenocortical cells.

scholarly journals Luteinizing Hormone-Induced Extracellular-Signal Regulated Kinase Activation Differently Modulates Progesterone and Androstenedione Production in Bovine Theca Cells

Endocrinology ◽  
2005 ◽  
Vol 146 (7) ◽  
pp. 2903-2910 ◽  
Author(s):  
Kimihisa Tajima ◽  
Kumiko Yoshii ◽  
Shin Fukuda ◽  
Makoto Orisaka ◽  
Kaoru Miyamoto ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Mrna Levels ◽  
Theca Cells ◽  
Progesterone Production ◽  
Erk Phosphorylation ◽  
Steroidogenic Acute Regulatory ◽  
Kinase A

Abstract It has been reported that gonadotropins promoted phosphorylation of ERK/MAPK in granulosa cells. However, little is known about the effects of gonadotropin on ERK activity in theca cells. This study explores how LH/forskolin controls ERK phosphorylation in cultured bovine theca cells. Effects of ERK on steroidogenesis were also investigated. Phosphorylation of ERK in bovine theca cells was augmented by LH and forskolin in 5 min; it decreased thereafter below basal levels in 20 min. Nevertheless, phosphorylation of the ERK kinase, MEK, was unaffected. Addition of H89 (a protein kinase A inhibitor) significantly reduced the effect of LH/forskolin on ERK phosphorylation. A potent MEK inhibitor PD98059 eliminated ERK phosphorylation and augmented progesterone production concomitantly with the elevation of intracellular steroidogenic acute regulatory protein mRNA in LH/forskolin-stimulated theca cells. In contrast to progesterone production, androgen production was diminished significantly by inhibition of ERK with decreased intracellular P450c17 mRNA levels. Taking these results together, we conclude that LH/cAMP leads to phosphorylation of ERK in a biphasic manner through MEK-independent pathway in bovine theca cells. Protein kinase A-induced phosphatase could possibly contribute to the phosphorylation process. Furthermore, modulation of ERK phosphorylation involves control of thecal steroidogenesis via modulation of the expression of steroidogenic acute regulatory protein and P450c17.

scholarly journals Novel Action of Activin and Bone Morphogenetic Protein in Regulating Aldosterone Production by Human Adrenocortical Cells

Endocrinology ◽  
2004 ◽  
Vol 145 (2) ◽  
pp. 639-649 ◽  
Author(s):  
Jiro Suzuki ◽  
Fumio Otsuka ◽  
Kenichi Inagaki ◽  
Masaya Takeda ◽  
Toshio Ogura ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Regulatory Protein ◽  
Mapk Signaling ◽  
Steroidogenic Acute Regulatory Protein ◽  
Mrna Levels ◽  
Type Ii ◽  
Ang Ii ◽  
Morphogenetic Protein ◽  
Aldosterone Production ◽  
Steroidogenic Acute Regulatory

Abstract We have uncovered a functional bone morphogenetic protein (BMP) and activin system complete with ligands (BMP-6 and activin βA/βB), receptors (activin receptor-like kinase receptors 2, 3, and 4; activin type-II receptor; and BMP type-II receptor), and the binding protein follistatin in the human adrenocortical cell line H295R. Administration of activin and BMP-6 to cultures of H295R cells caused concentration-responsive increases in aldosterone production. The mRNA levels of steroidogenic acute regulatory protein or P450 steroid side-chain cleavage enzyme, the rate-limiting steps of adrenocortical steroidogenesis, were enhanced by activin and BMP-6. Activin and BMP-6 also activated the transcription of steroidogenic acute regulatory protein as well as the late-step steriodogenic enzyme CYP11B2. Activin enhanced ACTH-, forskolin-, or dibutyryl-cAMP- but not angiotensin II (Ang II)-induced aldosterone production, whereas BMP-6 specifically augmented Ang II-induced aldosterone production. Activin and ACTH but not BMP-6 increased cAMP production. Follistatin, which inhibits activin actions by binding, suppressed basal and ACTH-induced aldosterone secretion but failed to affect the Ang II-induced aldosterone level. Furthermore, MAPK signaling appeared to be involved in aldosterone production induced by Ang II and BMP-6 because an inhibitor of MAPK activation, U0126, reduced the level of aldosterone synthesis stimulated by Ang II and BMP-6 but not activin. In addition, Ang II reduced the expression levels of BMP-6 but increased that of activin βB, whereas ACTH had no effect on these levels. Collectively, the present data suggest that activin acts to regulate adrenal aldosterone synthesis predominantly by modulating the ACTH-cAMP-protein kinase A signaling cascade, whereas BMP-6 works primarily by modulating the Ang II-MAPK cascade in human adrenal cortex in an autocrine/paracrine fashion.

Acute regulation of the bovine gene for the steroidogenic acute regulatory protein in ovarian theca and adrenocortical cells

2000 ◽  
Vol 24 (1) ◽  
pp. 109-118 ◽  
Author(s):  
R Ivell ◽  
G Tillmann ◽  
H Wang ◽  
M Nicol ◽  
PM Stewart ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Cell Cultures ◽  
Protein Biosynthesis ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Mrna Levels ◽  
Adrenocortical Cells ◽  
Theca Cells ◽  
Steroidogenic Acute Regulatory ◽  
Star Gene

Upregulation of the steroidogenic acute regulatory protein (StAR) is implicated in the rapid synthesis and secretion of steroidogenic cells to produce steroids in response to stimulation by trophic hormones of the gonadal and stress axes. In the present study, we have assessed the kinetics of both StAR gene transcription and protein biosynthesis in primary cell cultures of bovine adrenocortical and ovarian theca cells, under conditions of acute stimulation by corticotrophin (ACTH) and luteinizing hormone (LH), respectively. In both cell systems, detectable upregulation of StAR gene transcription occurred within 1-2 h, reaching maxima at 4 h (theca cells) or 6 h (adrenocortical cells). mRNA levels returned rapidly to baseline, by 12 h or 24 h, respectively. Specific StAR protein levels were assessed by western blotting using a novel antibody raised against a bovine StAR peptide, and showed a similar fast upregulation, albeit delayed by 1-2 h compared with the mRNA. The response of the cultured theca cells was more acute than that of the adrenocortical cells, possibly reflecting the propensity of the LH receptor to desensitize rapidly, unlike the ACTH receptor. The primary bovine theca cell cultures were also used for fully homologous transfection studies using various deletion promoter-reporter constructs of the bovine StAR gene. Kinetic analysis of the results indicated that the acute transcriptional response resides within the proximal (-315 bp) promoter region, which includes two putative responsive elements for the steroidogenic factor-1. More distal promoter regions may be involved in modulating the specificity of expression by combining enhancer and inhibitory functions.

scholarly journals Salinity, Temperature and Ammonia Acute Stress Response in Seabream (Sparus aurata) Juveniles: A Multidisciplinary Study

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 97
Author(s):  
Matteo Zarantoniello ◽  
Martina Bortoletti ◽  
Ike Olivotto ◽  
Stefano Ratti ◽  
Carlo Poltronieri ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Heat Shock ◽  
Acute Stress ◽  
Sparus Aurata ◽  
Fish Growth ◽  
Gilthead Seabream ◽  
Chemical Stress ◽  
Igf I ◽  
Cortisol Levels

The present study aimed to investigate the acute response of gilthead seabream (Sparus aurata) juveniles exposed to temperature, salinity and ammonia stress. Radioimmunoassay was used to evaluate cortisol levels, whereas insulin-like growth factors (igf1 and igf2), myostatin (mstn), heat-shock protein 70 (hsp70) and glucocorticoid receptor (gr) gene expression was assessed trough Real-Time PCR. The presence and localization of IGF-I and HSP70 were investigated by immunohistochemistry. In all the stress conditions, a significant increase in cortisol levels was observed reaching higher values in the thermic and chemical stress groups. Regarding fish growth markers, igf1 gene expression was significantly higher only in fish subjected to heat shock stress while, at 60 min, igf2 gene expression was significantly lower in all the stressed groups. Temperature and ammonia changes resulted in a higher mstn gene expression. Molecular analyses on stress response evidenced a time dependent increase in hsp70 gene expression, that was significantly higher at 60 min in fish exposed to heat shock and chemical stress. Furthermore, the same experimental groups were characterized by a significantly higher gr gene expression respect to the control one. Immunostaining for IGF-I and HSP70 antibodies was observed in skin, gills, liver, and digestive system of gilthead seabream juveniles.

scholarly journals GATA4 Reduction Enhances 3′,5′-Cyclic Adenosine 5′-Monophosphate-Stimulated Steroidogenic Acute Regulatory Protein Messenger Ribonucleic Acid and Progesterone Production in Luteinized Porcine Granulosa Cells

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5557-5567 ◽  
Author(s):  
Yvonne Y. Hui ◽  
Holly A. LaVoie
Keyword(s):  
Granulosa Cells ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Mrna Levels ◽  
Down Regulation ◽  
Lh Surge ◽  
Progesterone Production ◽  
Steroidogenic Acute Regulatory ◽  
Camp Induction ◽  
Star Gene

Previous studies with cultured granulosa cells implicated GATA4 in gonadotropin regulation of the steroidogenic acute regulatory protein (STAR) gene. Caveats to these prior studies exist. First, GATA4 levels are reduced in granulosa-luteal cells after the LH surge when GATA6 expression is relatively high. Second, STAR mRNA expression is negligible in granulosa cells until after the LH surge. Both exogenous GATA4 and GATA6 can transactivate STAR gene promoter constructs. We used an RNA interference (RNAi) approach to determine the contributions of GATA4 and GATA6 to cAMP analog regulation of the endogenous STAR gene in luteinizing granulosa cells. STAR mRNA was stimulated by cAMP under control RNAi conditions. Surprisingly, GATA4 reduction by its respective RNAi approximately doubled the cAMP induction of STAR mRNA. At 24 h cAMP treatment, this augmentation was abolished by co-down-regulation of GATA4+GATA6. GATA6 down-regulation by itself did not alter STAR mRNA levels. GATA4+GATA6 co-down-regulation elevated basal CYP11A mRNA at 24 h treatment but did not affect its induction by cAMP. Basal levels of HSD3B mRNA were reduced by GATA4 RNAi conditions leading to a greater fold induction of its mRNA by cAMP. Fold cAMP-stimulated progesterone production was enhanced by GATA4 down-regulation but not by GATA4+GATA6 co-down-regulation. These data implicate GATA6 as the facilitator in cAMP-stimulated STAR mRNA and downstream progesterone accumulation under reduced GATA4 conditions. Data also demonstrate that basal levels of GATA4/6 are not required for cAMP induction of the STAR gene. The altered ratio of GATA4 to GATA6 after ovulation may allow GATA6 to enhance STAR mRNA accumulation.

Von Hermaphroditos der griechischen Mythologie bis zu DSD der Moderne

Praxis ◽  
2008 ◽  
Vol 98 (1) ◽  
pp. 31-34
Author(s):  
Oestmann ◽  
Mullis ◽  
Stanga
Keyword(s):  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Sich Eine ◽  
Fand Sich ◽  
Steroidogenic Acute Regulatory

Wir berichten über eine heute 34-jährige Frau, die im Alter von 6 Monaten wegen rezidivierendem Erbrechen hospitalisiert werden musste. Als Ursache fand sich eine Nebenniereninsuffizienz mit Verminderung sämtlicher Hormone der Steroidhormonbiosynthese. Die weiteren Abklärungen ergaben bei dem phänotypisch weiblichen Säugling eine lipoide kongenitale adrenale Hyperplasie mit 46,XY DSD. 24 Jahre später konnte in der DNS-Sequenzanalyse ein homozygoter, in der Schweiz vorkommender Basenaustausch des steroidogenic acute regulatory protein-Gens gefunden werden, welcher zu einem Aminosäurenaustausch Leucin 260 Prolin (L260P) führt.

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