210 EXPRESSION OF mRNA ENCODING STEROIDOGENIC ENZYMES IN THE DEVELOPING BOVINE OVARY

2010 ◽  
Vol 22 (1) ◽  
pp. 263
Author(s):  
R. B. da Silva ◽  
E. S. Caixeta ◽  
P. Ripamonte ◽  
A. C. S. Castilho ◽  
C. Price ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cytochrome P450 ◽  
Expression Patterns ◽  
Regulatory Protein ◽  
Primordial Follicle ◽  
Hydroxysteroid Dehydrogenase ◽  
Steroidogenic Enzymes ◽  
Crown Rump Length ◽  
Fetal Ovary ◽  
Steroidogenic Acute Regulatory

Recent findings suggest a role for estradiol in the regulation of early folliculogenesis. Estradiol production is greatest in the fetal ovary during early gestation in cattle, and both estradiol and progesterone inhibit primordial follicle activation (Yang MY and Fortune JE 2008 Biol. Reprod. 78 (Suppl 6), 1153-1161). Aromatase expression is detected in early stages of bovine pregnancy (Garverick HA et al. 2009 Anim. Reprod. Sci. in press). The mechanisms controlling steroidogenesis in the bovine fetal ovary remain to be fully elucidated. The objective of this study was to assess mRNA expression patterns of enzymes involved in steroid production [steroidogenic acute regulatory protein (STAR), side-chain cleavage P450 (CYP11), cytochrome P450 17 alpha-hydroxylase (CYP17A1), 3 beta-hydroxysteroid dehydrogenase (3fi-HSD), aromatase cytochrome P450 (CYP19), and 17 beta-hydroxysteroid dehydrogenase (17fi-HSD)] in bovine fetal ovaries during gestation. Bovine fetal ovaries were obtained in a local slaughterhouse, fetal age was estimated by the crown-rump length, and samples were grouped according with days of gestation as follows: 60 (n = 5), 75 (n = 8), 90 (n = 6), 120 (n = 7), 150 (n = 7), and 210 (n = 6). Expression of mRNA encoding steroidogenic enzymes was determined by semiquantitative real-time RT-PCR using bovine-specific primers and cyclophilin A as endogenous control. Reverse transcription was performed with SuperScriptIII® (Invitrogen, Carlsbad, CA, USA) and PCR with Power SYBR green master mix (Applied Biosystems, Foster City, CA, USA) in an ABI Prism® 7500 (Applied Biosystems). Gene expression values were determined by the Pfaffl equation and effect of day of gestation on gene expression was analyzed with Fisher’s protected test, except when data were not normally distributed and nonparametric analysis was performed. Expression of mRNA encoding all steroidogenic enzymes was detected throughout gestation. The mRNA abundance of CYP17A1 and CYP19 was highest at 60 days of gestation and decreased thereafter (P < 0.05). Expression of all other genes did not significantly vary with time of gestation. In conclusion, all major enzymes required for steroidogenesis were expressed in the bovine fetal ovary. Expression of CYP17A1 and CYP19 was suppressed after 60 days of gestation, suggesting that these enzymes may be involved in the mechanisms controlling estradiol production and follicle formation in the bovine fetal ovary. Supported by CAPES and FAPESP.

scholarly journals Changes in mRNAs encoding steroidogenic acute regulatory protein, steroidogenic enzymes and receptors for gonadotropins during spermatogenesis in rainbow trout testes

2006 ◽  
Vol 189 (3) ◽  
pp. 541-554 ◽  
Author(s):  
M Kusakabe ◽  
I Nakamura ◽  
J Evans ◽  
P Swanson ◽  
G Young
Keyword(s):  
Cytochrome P450 ◽  
Rainbow Trout ◽  
Reproductive Cycle ◽  
Regulatory Protein ◽  
Hydroxysteroid Dehydrogenase ◽  
Steroidogenic Acute Regulatory Protein ◽  
Fsh Receptor ◽  
Steroidogenic Enzyme ◽  
Lh Receptor ◽  
Steroidogenic Acute Regulatory

In vertebrates, sperm development and maturation are directly regulated by gonadal steroid hormone secretion. The relationships among the expression of genes encoding steroidogenic proteins and receptors for gonadotropins, and testicular steroid production have not yet been comprehensively determined in male teleosts. In this study, the changes in levels of mRNAs encoding follicle-stimulating hormone (FSH) receptor, luteinizing hormone (LH) receptor, steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage, 3β-hydroxysteroid dehydrogenase/Δ5–4-isomerase, cytochrome P450 17α-hydroxylase/17,20-lyase, cytochrome P450 11β-hydroxylase, 11β-hydroxysteroid dehydrogenase and 20β-hydroxysteroid dehydrogenase were determined by real-time, quantitative PCR assays and related to changes in serum steroid levels throughout the reproductive cycle in male rainbow trout. Serum 11-ketotestosterone and 17α,20β-dihydroxy-4-pregnen-3-one levels were measured by RIA. Although the pattern of change in the mRNA levels for the enzymes was variable, the increases in steroidogenic enzyme mRNAs started prior to a significant increase of serum steroid levels. The patterns of transcript levels of FSH and LH receptors suggest that changes in StAR and steroidogenic enzyme transcripts are largely mediated by the FSH receptor during early and mid-spermatogenesis and by the LH receptor during late spermatogenesis and spermiation. Levels of StAR (10-fold) and P450 17α-hydroxylase/17,20-lyase (sevenfold) transcripts changed with the greatest magnitude and were closely related to the changes in serum steroids, suggesting that changes in StAR and P450 17α-hydroxylase/17,20-lyase abundance are likely to be the major influences on overall steroidogenic output during the reproductive cycle in male rainbow trout.

scholarly journals DAX-1 Expression in Human Adrenocortical Neoplasms: Implications for Steroidogenesis

1998 ◽  
Vol 83 (7) ◽  
pp. 2597-2600 ◽  
Author(s):  
M. Reincke ◽  
F. Beuschlein ◽  
E. Lalli ◽  
W. Arlt ◽  
S. Vay ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mrna Expression ◽  
Protein Gene ◽  
Regulatory Protein ◽  
Nuclear Hormone Receptor ◽  
Adrenocortical Tumors ◽  
Steroidogenic Acute Regulatory ◽  
Adrenocortical Carcinomas ◽  
Star Gene ◽  
Functional Phenotype

The DAX-1 gene encodes an orphan nuclear hormone receptor essential for normal fetal development of the adrenal cortex. Recently, DAX-1 has been shown to act as a transcriptional repressor of steroidogenic acute regulatory protein gene expression (StAR), suppressing steroidogenesis. We, therefore, investigated the expression of DAX-1 in a variety of adrenocortical tumors and compared the results with StAR mRNA expression. We found low or absent DAX-1 expression in aldosterone-producing adenomas (n=11: 35±11%; normal adrenals: 100±17%) and in aldosterone-producing adrenocortical carcinomas (n=2: 24 and 36%). Cortisol-producing adenomas showed intermediate DAX-1 expression (n=8; 92±16), as did 3 non-aldosterone-producing carcinomas (72, 132 and 132%). High DAX-1 expression was present in nonfunctional adenomas (n=3; 160±17%). In contrast to DAX-1, StAR mRNA expression did not show significant variations between groups. We did not detect the expected negative correlation between DAX-1 and StAR mRNA in adrenocortical tumors. These data suggest that high DAX-1 expression in adrenocortical tumors is associated with a non-functional phenotype whereas low DAX-1 expression favors mineralo-corticoid secretion. These effects on steroidogenesis are mediated by mechanisms other than repression of StAR gene expression. Our results indicate that DAX-1 may be one of the factors influencing the steroid biosynthesis of adrenocortical neoplasms.

scholarly journals Oxysterol Regulation of Steroidogenic Acute Regulatory Protein Gene Expression

1998 ◽  
Vol 273 (46) ◽  
pp. 30729-30735 ◽  
Author(s):  
Lane K. Christenson ◽  
Jan M. McAllister ◽  
Kumiko O. Martin ◽  
Norman B. Javitt ◽  
Tim F. Osborne ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Gene ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Steroidogenic Acute Regulatory

scholarly journals Porcine and Bovine Steroidogenic Acute Regulatory Protein (StAR) Gene Expression during Gestation1

Endocrinology ◽  
1997 ◽  
Vol 138 (3) ◽  
pp. 1085-1091 ◽  
Author(s):  
Nicolas Pilon ◽  
Isabelle Daneau ◽  
Chantal Brisson ◽  
Jean-François Ethier ◽  
Jacques G. Lussier ◽  
...  
Keyword(s):  
Gene Expression ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Steroidogenic Acute Regulatory ◽  
Star Gene

scholarly journals Immunoelectron microscopic localization of three key steroidogenic enzymes (cytochrome P450(scc), 3 beta-hydroxysteroid dehydrogenase and cytochrome P450(c17)) in rat adrenal cortex and gonads

2001 ◽  
Vol 171 (2) ◽  
pp. 373-383 ◽  
Author(s):  
G Pelletier ◽  
S Li ◽  
V Luu-The ◽  
Y Tremblay ◽  
A Belanger ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Steroid Hormones ◽  
Adrenal Cortex ◽  
Leydig Cells ◽  
Ultrastructural Localization ◽  
Hydroxysteroid Dehydrogenase ◽  
Cytochrome P450 Enzymes ◽  
Steroidogenic Enzymes ◽  
Adrenocortical Cells ◽  
Theca Interna

The biosynthesis of steroid hormones in endocrine steroid-secreting glands results from a series of successive steps involving both cytochrome P450 enzymes, which are mixed-function oxidases, and steroid dehydrogenases. So far, the subcellular distribution of steroidogenic enzymes has been mostly studied following subcellular fractionation, performed in placenta and adrenal cortex. In order to determine in situ the intracellular distribution of some steroidogenic enzymes, we have investigated the ultrastructural localization of the three key enzymes: P450 side chain cleavage (scc) which converts cholesterol to pregnenolone; 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) which catalyzes the conversion of 3 beta-hydroxy-5-ene steroids to 3-oxo-4-ene steroids (progesterone and androstenedione); and P450(c17) which is responsible for the transformation of C(21) into C(19) steroids (dehydroepiandrosterone and androstenedione). Immunogold labeling was used to localize the enzymes in rat adrenal cortex and gonads. The tissues were fixed in 1% glutaraldehyde and 3% paraformaldehyde and included in LR gold resin. In the adrenal cortex, both P450(scc) and 3 beta-HSD immunoreactivities were detected in the reticular, fascicular and glomerular zones. P450(scc) was exclusively found in large mitochondria. In contrast, 3 beta-HSD antigenic sites were mostly observed in the endoplasmic reticulum (ER) with some gold particles overlying crista and outer membranes of the mitochondria. P450(c17) could not be detected in adrenocortical cells. In the testis, the three enzymes were only found in Leydig cells. Immunolabeling for P450(scc) and 3 beta-HSD was restricted to mitochondria, while P450(c17) immunoreactivity was exclusively observed in ER. In the ovary, P450(scc) and 3 beta-HSD immunoreactivities were found in granulosa, theca interna and corpus luteum cells. The subcellular localization of the two enzymes was very similar to that observed in adrenocortical cells. P450(c17) could also be detected in theca interna cells of large developing and mature follicles. As observed in Leydig cells, P450(c17) immunolabeling could only be found in the ER. These results indicate that in different endocrine steroid-secreting cells P450(scc), 3 beta-HSD and P450(c17) have the same association with cytoplasmic organelles (with the exception of 3 beta-HSD in Leydig cells), suggesting similar intracellular pathways for biosynthesis of steroid hormones.

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