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Query: UNIPROT:Q7LGC8 (
HSD
)
3,196
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
It is hypothesized that the two-cell model for estrogen production by the ovarian follicle is preserved in the primate corpus luteum, but there is little direct evidence to support this theory. To determine the sites of androgen and estrogen synthesis within the primate corpus luteum and to ascertain whether changes in steroid hormone levels are related to steroidogenic enzyme expression, the enzymes converting progesterone to androgen (cytochrome P450 17alpha-hydroxylase/17,20 lyase; P450(c17)) and then to estrogen (aromatase; P450(arom)), as well as P450 side-chain cleavage (
P450(scc)
) and 3beta-hydroxysteroid dehydrogenase (3beta
HSD
), were detected by immunohistochemistry in macaque luteal tissue throughout the menstrual cycle and simulated early pregnancy. Corpora lutea were collected from rhesus monkeys in the early (Days 2-4 post-LH surge), mid (Days 6-8), mid-late (Days 10-12), and late (Days 14-15) luteal phase and after 1, 3, 6, or 9 days of hCG treatment that began on Day 9 of the luteal phase. Specific cytoplasmic staining for P450(c17), P450(arom),
P450(scc)
, and 3beta
HSD
was present in luteal cells, but not in the microvasculature, within all luteal tissues examined. P450(c17)-stained luteal cells were located along the vascular tracts and around the periphery of the corpus luteum. Intensely stained luteal cells were associated with blood vessels entering from the outer surface of the corpus luteum, but not with blood vessels returning from the connective tissue centrum. In contrast, P450(arom)-stained luteal cells were distributed throughout the luteal parenchyma. P450(c17) staining intensity was similar at all stages of the luteal phase; however, the number and intensity of P450(arom)-stained cells decreased by late luteal phase. In simulated early pregnancy, cells stained for P450(c17) were present near blood vessels, with some positive cells scattered throughout the corpus luteum. P450(arom) immunostaining was heterogeneous within the corpus luteum; many intensely stained cells were interspersed among others that were only lightly stained. Overall, cellular staining for P450(c17) and P450(arom) remained intense through 9 days of simulated early pregnancy. In contrast,
P450(scc)
and 3beta
HSD
immunoreactivity were not located in distinct luteal compartments. These results are consistent with a two-cell model for steroid hormone production in the primate corpus luteum, whereby paraluteal (theca-luteal) cells produce androgen substrate that is converted to estrogens by true (granulosa-) luteal cells. The divergence in enzyme detection as the luteal phase progresses, with P450(c17) labeling high and P450(arom) staining having decreased, suggests a shift in the function of the corpus luteum as it ages. Enzyme localization during chorionic gonadotropin exposure simulating early pregnancy demonstrates the continued capacity of the primate corpus luteum to produce steroid hormones.
...
PMID:Localization of steroidogenic enzymes in macaque luteal tissue during the menstrual cycle and simulated early pregnancy: immunohistochemical evidence supporting the two-cell model for estrogen production in the primate corpus luteum. 916 Jul 4
The unique characteristics of the primate (particularly human) fetal adrenal were first realized in the early 1900s when its morphology was examined in detail and compared with that of other species. The unusual architecture of the human fetal adrenal cortex, with its unique and disproportionately enlarged fetal zone, its compact definitive zone, and its dramatic remodeling soon after birth captured the interest of developmental anatomists. Many detailed anatomical studies describing the morphology of the developing human fetal adrenal were reported between 1920 and 1960, and these morphological descriptions have not changed significantly. More recently, it has become clear that fetal adrenal cortical growth involves cellular hypertrophy, hyperplasia, apoptosis, and migration and is best described by the migration theory, i.e. cells proliferate in the periphery, migrate centripetally, differentiate during their migration to form the functional cortical zones, and then likely undergo apoptosis in the center of the cortex. Consistent with this model, cells of intermediate phenotype, arranged in columnar cords typical of migration, have been identified between the definitive and fetal zones. This cortical area has been referred to as the transitional zone and, based on the expression of steroidogenic enzymes, we consider it to be a functionally distinct cortical zone. Elegant experiments during the 1950s and 1960s demonstrated the central role of the primate fetal adrenal cortex in establishing the estrogenic milieu of pregnancy. Those findings were among the first indications of the function and physiological role of the human fetal adrenal cortex and led Diczfalusy and co-workers to propose the concept of the feto-placental unit, in which DHEA-S produced by the fetal adrenal cortex is used by the placenta for estrogen synthesis. Tissue and cell culture techniques, together with improved steroid assays, revealed that the fetal zone is the primary source of DHEA-S, and that its steroidogenic activity is regulated by ACTH. In recent years, function of the human and rhesus monkey fetal adrenal cortical zones has been reexamined by assessing the localization and ontogeny of steroidogenic enzyme expression. The primate fetal adrenal cortex is composed of three functionally distinct zones: 1) the fetal zone, which throughout gestation does not express 3 beta
HSD
but does express
P450scc
and P450c17 required for DHEA-S synthesis; 2) the transitional zone, which early in gestation is functionally identical to the fetal zone but late in gestation (after 25-30 weeks) expresses 3 beta
HSD
,
P450scc
, and P450c17, and therefore is the likely site of glucocorticoid synthesis, and 3) the definitive zone, which lacks P450c17 throughout gestation but late in gestation (after 22-24 weeks) expresses 3 beta
HSD
and
P450scc
, and therefore is the likely site of mineralocorticoid synthesis. Indirect evidence, based on effects of P450c21 deficiency and maternal estriol concentrations, indicate that the fetal adrenal cortex produces cortisol and DHEA-S early in gestation (6-12 weeks). However, controversy exists as to whether cortisol is produced de novo or derived from the metabolism of progesterone, as data regarding the expression of 3 beta
HSD
in the fetal adrenal cortex early in gestation are conflicting. During the 1960s, Liggins and colleagues demonstrated that in the sheep, cortisol secreted by the fetal adrenal cortex late in gestation regulates maturation of the fetus and initiates the cascade of events leading to parturition. Those pioneering discoveries provided insight into the mechanism underlying the timing of parturition and therefore were of particular interest to obstetricians and perinatologists confronted with the problems of preterm labor. However, although cortisol emanating from the fetal adrenal cortex promotes fetal maturation in primates as it does in sheep, its role in the regulation of primate parturition, unlike that in sheep
...
PMID:Developmental and functional biology of the primate fetal adrenal cortex. 918 69
TGF beta1 has been detected by immunohistochemistry in the rat fetal testis. Therefore, we attempted to determine whether this factor can act as a local regulator of Leydig cell function during fetal development. An inhibitory effect of TGF beta1 on basal and luteinizing hormone (LH)-stimulated testosterone secretion by fetal testes in vitro was observed only with testes from 13.5 day-old fetuses and not with testes from older stages. The lack of effect of exogenous TGF beta1 in organ culture after day 13.5 might be related to an elevated intratesticular concentration that would already exert maximal biological effect. On the contrary, in a model of dispersed testicular cells in culture, TGF beta1 was able to inhibit LH-stimulated testosterone production by fetal Leydig cells from 16.5 and 20.5 day-old fetuses. This inhibition of LH-stimulated testosterone production was dose- and time-dependent and was maximal after 48 h of treatment with 1 ng/ml TGF beta1, with testosterone secretion being reduced to 25% of control values. Inhibition of testosterone secretion was also observed in basal and dbcAMP-stimulated conditions, suggesting that one site of action of TGF beta1 is located after the production of cAMP. However, TGF beta1 was also able to inhibit LH-induced cAMP production. As demonstrated by the transformation of steroidogenic precursors into testosterone, TGF beta1 did not significantly alter 3beta-hydroxysteroid dehydrogenase (3beta
HSD
) activity but induced a strong inhibition of cytochrome P450 17alpha-hydroxylase/C17-20 lyase (P450C17) activity which was associated with a marked diminution of cytochrome P450C17 mRNA levels (26% of control values) but not of cytochrome
P450scc mRNA
. In addition to its effect on steroidogenesis, TGF beta1 exhibited morphogenic actions on the fetal testicular cells, inducing spreading when the cells were adherent and aggregation when the cells were cultured in conditions of lesser adherence and without any significant effect on either total cell number or 3beta
HSD
positive cells. Taken together these results suggest that TGF beta1 likely plays a morphogenic and physiological role very early in the fetal testis via paracrine/autocrine mechanisms.
...
PMID:Transforming growth factor beta1 inhibits steroidogenesis in dispersed fetal testicular cells in culture. 925 60
A 48-year-old woman with Cushing's syndrome due to bilateral adrenocortical adenomas is reported. The patient presented with a typical Cushingoid appearance. The serum cortisol level was elevated with loss of the diurnal rhythm and the plasma adrenocorticotropic hormone (ACTH) level was undetectable. Dynamic testing showed no suppression of urinary 17-OHCS by high-dose dexamethasone and no stimulation by metyrapone. An abdominal computed tomography (CT) scan showed bilateral adrenal tumors. Bilateral adrenalectomy was performed. The right adrenal gland contained a tumor that was encapsulated and consisted mainly of compact cells. The surrounding cortex was atrophic. The left adrenal gland contained an encapsulated tumor composed predominantly of clear cells. There were numerous small adrenocortical nodules in the surrounding cortex. Immunohistochemical analysis of steroidogenic enzymes (
P450scc
, 3beta-
HSD
, P450c21, P450c17 and P450c11) was performed. Immunoreactivity of all the enzymes was intense in the compact cells of the right adrenocortical adenoma, while the adjacent non-neoplastic cortex was negative for the enzymes. In the left adrenal tumor, the immunoreactivity of 3beta-
HSD
was intense, while that of P450c17 was weak. In the adrenocortical nodules, 3beta-
HSD
activity was sporadically observed. G protein genes encoding Gs alpha and Gi2 were examined for activating mutations at codons 201 and 227 (Gs alpha) and codons 179 and 205 (Gi2 alpha) in the bilateral adrenal tumors, but no mutations were found. The bilateral adenomas of this patient showed marked differences in microscopic and immunohistochemical studies, suggesting that the capacity of steroidogenesis differs between the right and left tumors.
...
PMID:Cushing's syndrome due to bilateral adrenocortical adenomas with different pathological features. 939 54
In the analysis of the regulation of human corpus luteum, it is very important to localize the sites of specific steroid hormone production to obtain a better understanding of luteal function. We have examined expression of steroidogenic enzymes, steroid receptors, and adrenal 4 binding protein (Ad4BP), a transcription factor of steroidogenesis, in corpus luteum of normal cycling human ovary. Corpus luteum can be classified into four different stages from ovulation to complete regression or fibrosis based on these findings: (1) corpus luteum, (2) steroid-producing degenerating corpus luteum or SPDCL, (3) nonsteroid producing or NSPDCL, and (4) corpus albicans. Corpus luteum in the luteal phase is characterized as follows: (a) the expression of
P450scc
(
cholesterol side chain cleavage)
, 3 beta
HSD
(hydroxysteroid dehydrogenase), and Ad4BP in almost all the luteinized granulosa and theca cells, consistent with active progesterone biosynthesis; (b) expression of estrogen-producing P450arom (aromatase) in luteinized granulosa cells, indicating active estrogen production and that of P450c17 (17 alpha hydroxylase) in luteinized theca cells, and (c) expression of progesterone receptor (PR) and androgen receptor (AR) in both luteinized granulosa and theca cells. SPDCL correspond to corpus luteum undergoing regression or degeneration in the following cycle and are characterized as follows: (a) absence of all the steroidogenic enzymes and Ad4BP in the luteinized granulosa cells, suggestive of hormonally inactive nature of these cells and (b) marked expression of
P450scc
, 3 beta
HSD
, P450c17 and Ad4BP in luteinized theca cells. NSPDCL is characterized as the absence of all the steroidogenic enzymes and sporadic expression of Ad4BP in luteinized theca cells. These findings indicate that luteal cells remain even after losing expression of steroidogenic enzymes, consistent with a prolonged process of degeneration or regression of human corpus luteum. In corpus albicans, all the cells were replaced by fibrosis and steroidogenic enzymes; steroid receptors and Ad4BP were not expressed at all. Localization of steroidogenesis in human corpus luteum has thus provided new insights into understanding of its biological features.
...
PMID:Localization of steroidogenesis and steroid receptors in human corpus luteum. Classification of human corpus luteum (CL) into estrogen-producing degenerating CL, and nonsteroid-producing degenerating CL. 958 Sep 43
Immune-endocrine interactions are important to the regulation of Leydig cell steroidogenesis. We have shown previously that both tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1-beta) inhibit 8-bromo-cAMP-(8-Br-cAMP)-stimulated steroidogenesis in mouse Leydig cells. TNF and IL-1 both inhibit cAMP-stimulated testosterone production as well as mRNA and protein levels of cholesterol side chain cleavage enzyme (
P450scc
) and 17 alpha-hydroxylase/C17,20 lyase (P450c17) in mouse Leydig cells. Neither TNF nor IL-1 affects basal levels of
P450scc mRNA
and protein. In the present study, we tested the effects of TNF and IL-1 on basal testosterone production and 8-Br-cAMP-stimulated 3 beta-hydroxysteroid dehydrogenase/delta 5-->delta 4 isomerase (3 beta
HSD
) expression in Leydig cells. Purified and macrophage-depleted Leydig cells were cultured for 5 d with daily changes of media, and then treated with increasing concentrations of recombinant mouse TNF or IL-1 in the presence or absence of 8-Br-cAMP (50 microM) for 24 h. The media were collected for testosterone RIA and RNA and protein were extracted from cells. Basal testosterone production was inhibited by TNF, but not IL-1. Treatment of Leydig cells with 8-Br-cAMP alone caused a marked increase in 3 beta
HSD
mRNA, and protein levels. Both TNF and IL-1 inhibited cAMP-stimulated 3 beta
HSD
mRNA and protein levels, but only TNF inhibited basal 3 beta
HSD
expression. These results demonstrate that TNF and IL-1 have different effects on basal steroidogenesis in Leydig cells and suggest that TNF-mediated inhibition of basal testosterone production may be owing to the inhibition of basal 3 beta-HSD expression in Leydig cells.
...
PMID:Differential effects of tumor necrosis factor-alpha and interleukin-1 on 3 beta-hydroxysteroid dehydrogenase/delta 5-->delta 4 isomerase expression in mouse Leydig cells. 965 65
Ovarian follicular development in cattle is characterized by waves of growth during the prepubertal and postpartum periods and during estrous cycles. Each wave of follicular growth is characterized by recruitment of a cohort of follicles 4 to 5 mm in diameter. From the cohort, one follicle is selected for continued growth and becomes dominant. If luteolysis occurs during the growth phase of dominant follicles, final maturation and ovulation occurs. If luteolysis does not occur during the growing and maintenance phase of follicles, the fate is atresia. Changes in mRNA expression for the gonadotropin receptors (FSHr and LHr), key steroidogenic enzymes (cytochrome P450 side chain cleavage [
P450scc
], cytochrome P450 17alpha-hydroxylase-[P450c17], cytochrome P450 aromatase [P450arom], and 3beta-hydroxysteroid dehydrogenase [3beta-
HSD
]), and growth factors (IGF-I and -II) and their binding proteins (IGFBP) have been associated with different stages of follicular growth and atresia. In general, expression of mRNA for the gonadotropin receptors, steroidogenic enzymes, and steroidogenic acute regulatory protein (StAR) increase with progressive follicular development and is highest when dominant follicles approach maximum size. Expression of mRNA declines rapidly and becomes low or undetectable in atretic follicles. The IGF-I (granulosal cells) and IGF-II (thecal cells) are increased, whereas IGFBP-2 (granulosal cells) is reduced, in dominant follicles. Recruitment of a cohort of follicles is associated with initiation of expression of mRNA for
P450scc
and P450arom in granulosal cells. Selection of dominant follicles is associated with expression of mRNA for LHr and 3beta-
HSD
in granulosal cells. Thus, changes in gene expression likely are important to recruitment, selection, dominance, and atresia in ovarian follicles.
...
PMID:Expression of steroidogenic enzyme and gonadotropin receptor genes in bovine follicles during ovarian follicular waves: a review. 969 Jun 47
Neurosteroids are now known to be synthesized de novo in the nervous system through mechanisms at least partly independent of peripheral steroidogenic glands. In mammals, the presence of the cholesterol side-chain cleavage enzyme (cytochrome
P450scc
) and the enzyme 3beta-hydroxysteroid dehydrogenase/Delta5-Delta4-isomerase (3beta-HSD) has been well established in the brain, whereas limited information has been available on the enzyme 17alpha-hydroxylase/c17, 20-lyase (cytochrome P450c17), which converts pregnenolone to dehydroepiandrosterone, one of the most abundant neurosteroids. In addition, little is known regarding developmental changes in these steroidogenic enzymes during postnatal life. Thus, the pathway of neurosteroid formation in the brain is still incomplete. Therefore, we examined expressions of the messenger RNAs (mRNAs) encoding for three key enzymes,
P450scc
, P450c17 and 3beta-
HSD
, in the rat brain at different postnatal ages using RT-PCR analysis. The expression of
P450scc mRNA
was found throughout the brain at the same level, while the 3beta-
HSD
mRNA expression was higher in the cerebellum and cerebrum than in other brain regions. The P450c17 mRNA was highly expressed in the mesencephalon. On the other hand, higher expressions of the cerebellar and cerebral 3beta-
HSD
mRNAs were observed only in neonatal life. In contrast, the expression of
P450scc mRNA
was relatively constant during neonatal life and in adulthood. A similar constant expression of the P450c17 mRNA was evident in the mesencephalon. Serial Southern hybridization in this study confirmed the specific mRNA expression corresponding to each enzyme. These results suggest that in the postnatal rat the expression of 3beta-
HSD
or P450c17 mRNA may be age- or region-dependent, unlike the
P450scc mRNA
expression.
...
PMID:Age- and region-specific expressions of the messenger RNAs encoding for steroidogenic enzymes p450scc, P450c17 and 3beta-HSD in the postnatal rat brain. 972 6
DAX-1 is an unusual member of the nuclear hormone receptor superfamily whose expression is mainly, but not uniquely, restricted to steroidogenic tissues. We have recently shown that DAX-1 can block the first and rate-limiting step in steroid biosynthesis by repressing StAR (steroidogenic acute regulatory protein) expression. Here we show that DAX-1 blocks steroid production at multiple levels in the Y-1 mouse adrenocortical tumor cell line. Expression of DAX-1 in Y-1 cells significantly impairs both basal and cAMP-stimulated steroid production, without affecting the functionality of the cAMP-responsive PKA pathway. Experiments using an hydroxylated cholesterol derivative show that biochemical steps in steroidogenesis subsequent to cholesterol delivery to mitochondria are also impaired in Y-1 cells expressing DAX-1. This is explained by the repression of
P450scc
and 3beta-
HSD
expression, in addition to StAR. DAX-1 expression in Y-1 cells results in the inhibition of the activity of the StAR,
P450scc
and 3beta-
HSD
promoters. An inappropriate steroidogenic block in the male fetus might have an important role in the pathogenesis of sex reversal syndromes caused by a duplication of the genomic region of the X chromosome containing the DAX-1 gene.
...
PMID:DAX-1 blocks steroid production at multiple levels. 975 5
P450scc
and 3beta-
HSD
cDNA were isolated from a zebrafish lambda gt10 cDNA library using trout SCC and 3beta-
HSD
cDNA as the probes. The zebrafish SCC cDNA encodes a protein of 509 amino acids, which shares a 78% similarities with the trout SCC and 58% with the human SCC. As for 3beta-
HSD
, two forms of cDNA were isolated, termed
HSD
5 and
HSD
17, which may have resulted from alternative splicing.
HSD
5 and
HSD
17 encode proteins of 374 and 341 amino acids respectively. Both share 77% amino acid similarities with trout 3beta-
HSD
and 53% similarities with the mouse 3beta-
HSD
. Zebrafish has been increasingly used as a genetic model system to study organ development and to investigate human diseases. The cloning and the characterization of zebrafish
P450scc
and 3beta-
HSD
should facilitate study of steroidogenesis and human disease associated with steroid imbalance.
...
PMID:Cloning of zebrafish cDNA for 3beta-hydroxysteroid dehydrogenase and P450scc. 988 98
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