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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Testicular peritubular cells produce paracrine mediators which modulate Sertoli cell function. The production of these mediators (P Mod-S) is controlled by androgens suggesting that mesenchymal-epithelial interactions play an important role in androgen action in the testis. We investigated whether mesenchymal cells from the prostate, another androgen target tissue, produce analogous mediators. To this end rat Sertoli cell cultures were exposed to dialyzed spent media derived from testicular peritubular cells, prostatic stromal cells or footsole fibroblasts. It is demonstrated that the effects of spent media from peritubular cells and stromal cells are nearly identical: they stimulate the production of androgen binding protein and transferrin and they inhibit FSH-inducible aromatase activity. The active principle (or principles) involved is non-dialyzable, heat sensitive and trypsin sensitive. Its production is markedly stimulated by androgens. Fibroblast spent media are inactive. It is concluded that mesenchymal tissue derived from different androgen target tissues may produce identical or similar mediators of androgen action acting on epithelial cells.
Mol Cell Endocrinol 1989 Mar
PMID:Stromal cells from the rat prostate secrete androgen-regulated factors which modulate Sertoli cell function. 274 20

The role of basic fibroblast growth factor (bFGF) in ovarian granulosa cell differentiation was investigated in vitro. To this end, use was made of a primary culture of rat granulosa cells the differentiation of which was monitored by the acquisition of aromatase activity. Concurrent treatment with highly purified bFGF (10 ng/ml) produced a significant (P less than 0.05), albeit reversible inhibition (88 +/- 6%) of FSH (but not basal)-supported aromatization. Although independent of the FSH dose employed and of cell density, bFGF-attenuated aromatase activity proved dose-dependent, with a projected minimal effective dose of 0.11 +/- 0.03 ng/ml (7.5 +/- 2 pM), and an apparent median inhibitory dose of 0.63 +/- 0.09 ng/ml (43 +/- 6 pM). Unaccounted for by alterations in granulosa cell number, plating efficiency, or viability, the ability of bFGF to attenuate FSH hormonal action proved partly attributable to site(s) of action distal, rather than proximal to cAMP generation. Taken together, these observations indicate that the cytodifferentiative and replicative actions of bFGF in the granulosa cell can be dissociated, and lend additional support to the prospect that bFGF, possibly of intraovarian origin, may play a role in granulosa cell differentiation in the course of their ontogeny.
Mol Cell Endocrinol 1988 Jan
PMID:Basic fibroblast growth factor as a regulator of ovarian granulosa cell differentiation: a novel non-mitogenic role. 283 42

Aromatase is an enzyme complex that is composed of a specific form of cytochrome P-450 and a flavoprotein, NADPH-cytochrome P-450 reductase. Aromatase activity of granulosa cells is increased markedly by follicle-stimulating hormone (FSH) and by analogs of cyclic AMP. It was the objective of the present study to investigate the effects of FSH and dibutyryl cyclic AMP (Bt2cAMP) on the synthesis of NADPH-cytochrome P-450 reductase in rat granulosa cells maintained in vitro. Granulosa cells were obtained from the ovaries of diethylstilbestrol (DES)-treated immature rats and were incubated in the presence of DES (10(-7) M), DES + FSH (250 ng/ml), or DES + Bt2cAMP (1 mM) for up to 72 h. After 72 h of incubation, aromatase activity of cells incubated with DES alone was 5 pmoles estrogen formed 2 h-1 mg-1 protein and was increased greater than 60-fold in cells incubated with FSH or Bt2cAMP. NADPH-cytochrome P-450 reductase was immunoisolated from [35S]methionine-labeled lysates of granulosa cells incubated for 72 h in the absence or presence of stimulatory factors. The rate of synthesis of reductase was found to be increased about 3-fold in cells incubated with DES + FSH or DES + Bt2cAMP as compared to cells incubated with DES alone. By immunoblot analysis we found that the cellular content of reductase was increased about 2-fold by FSH and Bt2cAMP treatment. Reductase specific activity was 10 nmoles min-1 mg-1 protein in membrane fractions of DES-treated cells and was increased 1.6-fold by FSH treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Endocrinol 1985 May
PMID:Regulation of aromatase activity of rat granulosa cells: induction of synthesis of NADPH-cytochrome P-450 reductase by FSH and dibutyryl cyclic AMP. 298 33

Antibodies were obtained against both protein components of the cytochrome P-450 enzyme system responsible for estrogen biosynthesis, estrogen synthetase (aromatase), from human placental microsomes. The antiserum against the NADPH-cytochrome P-450 reductase component (antiserum denoted RE-DFBIV) gave a single major band at the Mr of the authentic enzyme by immunoblotting after electrophoretic separation of SDS-solubilized microsomes and inhibited both the reductase and aromatase activities in human placental and endometrial microsomes (Tseng, L. and Bellino, F.L. (1985) J. Steroid Biochem. 22, 555-557) and in homogenates of cultured aromatase-stimulated human endometrial stromal cells and human ovarian microsomes. The antiserum against the cytochrome P-450 component of aromatase (antiserum denoted P45FBIII) also gave a single band at the Mr of the authentic protein by immunoblotting after electrophoresis, and inhibited aromatase activity in homogenates of human placental microsomes, ovarian and decidual particulate fractions and cultured aromatase-stimulated endometrial stromal cells. This antiserum had no effect on NADPH-cytochrome c reductase activity in any of the systems studied. We conclude that these antiserum preparations separately recognize the NADPH-cytochrome P-450 reductase and cytochrome P-450 components of aromatase in human placenta, ovary, decidua and endometrium. Epitopes on these aromatase component proteins involved in enzyme activity are shared among these various human tissue sources.
Mol Cell Endocrinol 1987 Jul
PMID:Antisera against estrogen synthetase from human placental microsomes. Antibody characterization and cross-reactivity studies in other organs. 311 25

We studied the effects of androgens on basal and FSH-stimulated aromatase activity in Sertoli cell-enriched monolayers. Daily exposure to androgens from the first day of culture results in a time- and dose-dependent decrease in inducible aromatase activity. The inhibition is observed whether FSH, L-isoproterenol or (Bu)2cAMP is used as inducer of the aromatase activity. Basal activity is not affected by preincubation with androgens and the inhibitory effect is not observed after short-term exposure (24 h) to these hormones. The ability of different androgens to decrease inducible aromatase activity does not depend on their ability to serve as a substrate for the aromatase but parallels their ability to stimulate the production of androgen-binding protein. Moreover, the effect of testosterone is neutralized by the antiandrogen cyproterone acetate, suggesting that it is mediated by the androgen receptor. These data suggest that testicular androgens may be responsible for the decrease in FSH-inducible aromatase activity observed in intact rats between days 10 and 30 of life. Similarly, the removal of these androgens during the preparation of Sertoli cell cultures may explain the spontaneous increase in inducible aromatase activity observed when these cultures are maintained in the absence of androgens.
Mol Cell Endocrinol 1988 May
PMID:Prolonged exposure to androgens suppresses follicle-stimulating hormone-induced aromatase activity in rat Sertoli cell cultures. 313 15

Parturition in the pregnant sheep is preceded by an abrupt alteration in placental steroid metabolism causing a shift from progesterone to estrogen production. This change is believed to be a consequence of the prepartum rise in cortisol in the fetal circulation and involves increases in activities of the enzymes steroid 17 alpha-hydroxylase (cytochrome P-450(17)alpha), steroid C-17,20-lyase, and possibly aromatase. We have investigated the activity levels of aromatase and 17 alpha-hydroxylase in placental microsomes in late pregnancy and dexamethasone-induced labor. Over the gestational period of 118-140 days basal levels of placental aromatase were relatively constant [mean value (+/- SD) of 5.6 +/- 1.6 pmol min-1 mg microsomal protein-1 (n = 10)]. Steroid 17 alpha-hydroxylase activity was undetectable [less than 0.5 pmol min-1 mg microsomal protein-1 (n = 7)]. In six animals in labor induced with infusion of dexamethasone into the fetus, placental aromatase activity had a mean value of 14.0 +/- 2.5 pmol min-1 mg protein-1; placental steroid 17 alpha-hydroxylase, measured in four of the animals, had a mean (+/- SD) activity of 319 +/- 58 pmol min-1 mg microsomal protein-1. Immunoblotting of placental microsomal preparations with specific antibodies to cytochrome P-450(17)alpha and NADPH-cytochrome P-450-reductase indicated that the glucocorticoid-induced activity of 17 alpha-hydroxylase was associated with increased content of cytochrome P-450(17)alpha. Northern blotting with a cDNA probe for cytochrome P-450(17)alpha showed that glucocorticoid increased the levels of mRNA for the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1988 Mar
PMID:The regulation of ovine placental steroid 17 alpha-hydroxylase and aromatase by glucocorticoid. 313 86

Potential side-effects of the immunosuppressive drug cyclosporine (also cyclosporin A, CsA) on ovarian endocrine function have been investigated using granulosa cells isolated from immature estrogen-primed rats and cultured in a chemically defined medium. The FSH-dependent differentiation of steroidogenic pathways for estrogen and progestin secretion was shown to be differentially affected by CsA in vitro, at drug concentrations that approximate immunosuppressive concentrations in blood of humans or animals. CsA at 0.1-1 microgram/ml synergistically enhanced FSH-stimulated aromatase activity as measured by the conversion of exogenous testosterone to 17 beta-estradiol, while production of the progestins (progesterone + 20 alpha-hydroxypregn-4-en-3-one + pregnenolone) was little affected at up to 0.1 microgram/ml CsA and reduced at higher concentrations. CsA alone did not stimulate basal steroid secretion. The action of CsA to augment FSH-stimulated induction of aromatase activity was seen both in the presence or absence of testosterone. The effects of CsA (1 microgram/ml), either stimulatory on aromatase activity or inhibitory on progestin secretion, were in general increased with greater times of cell exposure throughout the culture period, although the temporal effects on 17 beta-estradiol and the progestins were not identical following delayed addition or removal of CsA from the culture medium. Higher concentrations of CsA (3-10 micrograms/ml) were generally toxic to granulosa cells as indicated by marked decreases in 17 beta-estradiol and progestin secretion and in incorporation of [3H]leucine. These results suggest that therapeutic concentrations of CsA might directly influence ovarian function by differentially modulating the FSH-dependent steroidogenic pathways of granulosa cells.
Mol Cell Endocrinol 1988 Jun
PMID:Cyclosporine differentially affects estrogen and progestin synthesis by rat granulosa cells in vitro. 313 44

The effects of FSH to increase the activity of aromatase, as well as the synthesis of the components of the aromatase enzyme complex, have been studied in human ovarian granulosa cells obtained from women undergoing oocyte retrieval. FSH increased aromatase activity, as well as the synthesis of aromatase cytochrome P-450 (P-450AROM) in a time-dependent fashion, whereas in the absence of FSH, both activity and synthesis declined with duration of culture. The effect of FSH was mimicked by forskolin, an activator of adenylate cyclase. FSH also increased the synthesis of NADPH-cytochrome P-450 reductase, but to a relatively modest extent. The levels of hybridizable mRNA species encoding cytochrome P-450AROM of lengths 3.0, 2.4, and 1.6 kilobases were also increased with FSH treatment. It is concluded that the regulation of aromatase activity by FSH in human granulosa cells is mediated primarily by changes in the synthesis of cytochrome P-450AROM, that this action of FSH is mediated by cAMP, and that the changes in cytochrome P-450AROM synthesis are the consequences of changes in the levels of mRNA encoding this enzyme.
Mol Endocrinol 1987 Jul
PMID:Regulation by follicle-stimulating hormone of the synthesis of aromatase cytochrome P-450 in human granulosa cells. 315 62

The effects of growth factors to regulate the activity of aromatase, as well as the synthesis of aromatase cytochrome P-450 (P-450AROM) have been studied in human ovarian granulosa cells obtained from women undergoing oocyte retrieval. Insulin-like growth factor I (IGF-I) increased aromatase activity as well as the synthesis of P-450AROM, in a concentration-dependent fashion. The levels of hybridizable mRNA species encoding cytochrome P-450AROM were also increased with IGF-I treatment. By contrast, epidermal growth factor (EGF) had no effect on these parameters when added alone, but markedly inhibited the action of follicle-stimulating hormone (FSH) to stimulate aromatase activity, and the synthesis of cytochrome P-450AROM, as well as its ability to increase the levels of mRNA encoding the enzyme. It is concluded that these growth factors have opposite effects on aromatase activity, and that these actions reflect, in part, changes in the synthesis of cytochrome P-450AROM, which in turn are the consequence of changes in the levels of mRNA encoding this enzyme.
Mol Cell Endocrinol 1988 Sep
PMID:Effects of epidermal growth factor and insulin-like growth factor I on the levels of mRNA encoding aromatase cytochrome P-450 of human ovarian granulosa cells. 326 56

To investigate the nature of the interactions between growth hormone (GH), insulin-like growth factor-I (IGF-I) and follicle stimulating hormone (FSH), their temporal and dose-related effects on steroidogenesis were studied in granulosa cells from stilboestrol-treated immature rats, stimulated in vitro with pregnant mare's serum gonadotropin (PMSG) or FSH. GH in the presence of PMSG enhanced aromatase activity and progesterone synthesis above that induced by maximally stimulating doses of PMSG alone, and accelerated PMSG-induced peak levels for both progesterone and aromatase activity. IGF-I also enhanced PMSG-induced aromatase activity and progesterone production, and accelerated their peak responses in a similar fashion to the effects observed for GH. The stimulatory actions of IGF-I could still be observed after the removal of FSH from the cultures, and appeared to be partly independent of cAMP. It is concluded that both GH and IGF-I act on FSH-induced granulosa cells to accelerate the differentiation of the follicular cell to a lutein cell.
Mol Cell Endocrinol 1988 Jan
PMID:Growth hormone and insulin-like growth factor-I accelerate PMSG-induced differentiation of granulosa cells. 336 Feb 8


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