scholarly journals Concerted Regulation of the Porcine Steroidogenic Acute Regulatory Protein Gene Promoter Activity by Follicle-Stimulating Hormone and Insulin-Like Growth Factor I in Granulosa Cells Involves GATA-4 and CCAAT/Enhancer Binding Protein β

Endocrinology ◽  
2004 ◽  
Vol 145 (7) ◽  
pp. 3122-3134 ◽  
Author(s):  
Holly A. LaVoie ◽  
Dheer Singh ◽  
Yvonne Y. Hui
Keyword(s):  
Growth Factor ◽  
Promoter Activity ◽  
Protein Gene ◽  
Follicle Stimulating Hormone ◽  
Regulatory Protein ◽  
Gene Promoter ◽  
Steroidogenic Acute Regulatory Protein ◽  
Factor I ◽  
Enhancer Binding Protein ◽  
Steroidogenic Acute Regulatory

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.

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