Biosynthesis of steroids by granulosa cells of the porcine ovary in vitro

Phosphoramide mustard exposure induces DNA adduct formation and the DNA damage repair response in rat ovarian granulosa cells

Phosphoramide mustard (PM), the ovotoxic metabolite of the anti-cancer agent cyclophosphamide (CPA), destroys rapidly dividing cells by forming NOR-G-OH, NOR-G and G-NOR-G adducts with DNA, potentially leading to DNA damage. A previous study demonstrated that PM induces ovarian DNA damage in rat ovaries. To investigate whether PM induces DNA adduct formation, DNA damage and induction of the DNA repair response, rat spontaneously immortalized granulosa cells (SIGCs) were treated with vehicle control (1% DMSO) or PM (3 or 6μM) for 24 or 48h. Cell viability was reduced (P<0.05) after 48h of exposure to 3 or 6μM PM. The NOR-G-OH DNA adduct was detected after 24h of 6μM PM exposure, while the more cytotoxic G-NOR-G DNA adduct was formed after 48h by exposure to both PM concentrations. Phosphorylated H2AX (γH2AX), a marker of DNA double stranded break occurrence, was also increased by PM exposure, coincident with DNA adduct formation. Additionally, induction of genes (Atm, Parp1, Prkdc, Xrcc6, and Brca1) and proteins (ATM, γH2AX, PARP-1, PRKDC, XRCC6, and BRCA1) involved in DNA repair were observed in both a time- and dose-dependent manner. These data support that PM induces DNA adduct formation in ovarian granulosa cells, induces DNA damage and elicits the ovarian DNA repair response.

Effects of growth hormone and growth hormone-releasing hormone on steroid synthesis in cultured human luteinizing granulosa cells

To assess the direct effect of growth hormone and growth hormone-releasing hormone on gene expression of steroidogenic enzymes and production of progesterone, 17-hydroxyprogesterone (17-OHP) and estradiol, we cultured luteinizing granulosa cells with or without follicle-stimulating hormone (FSH), growth hormone and growth hormone-releasing hormone at different concentrations. Luteinizing granulosa cells were obtained from women undergoing an in vitro fertilization program in the Department of Obstetrics and Gynecology, S. Raffaele Scientific Institute, Milan, Italy. At a concentration of 1 microgram/ml, FSH significantly increased estradiol production (2.1 +/- 0.7-fold the control value; p < 0.05 vs. control) and progesterone production (3.5 +/- 2.0-fold the control value; p < 0.05 vs. control). Growth hormone was effective on estradiol, progesterone and 17-OHP at 1 microgram/ml, enhancing estradiol production (1.3 +/- 0.2-fold the control value; p < 0.05 vs. control), progesterone production (2.5 +/- 1.0-fold the control value; p < 0.05 vs. control), and 17-OHP (1.4 +/- 0.2-fold the control value; p < 0.05 vs. control). Growth hormone-releasing hormone increased estradiol production (1.5 +/- 1.2-fold the control value) and progesterone production (1.3 +/- 0.8-fold the control value), but not significantly. No effects by growth hormone-releasing hormone were seen on 17-OHP production. FSH, growth hormone and growth hormone-releasing hormone did not increase P450scc and P450 aromatase mRNAs, whereas FSH increased P450c17 mRNA to 150% at 100 ng/ml and 1 microgram/ml, growth hormone increased it to 230% at 100 ng/ml and to 200% at 1 microgram/ml, and growth hormone-releasing hormone increased it to 140% at 100 ng/ml and to 190% of control values at 1 microgram/ml. These results indicate a direct effect of growth hormone on steroidogenesis by increasing P450c17 mRNA accumulation and progesterone, 17-OHP and estradiol production.

Regulation of ovarian steroidogenesis in vitro in the viviparous shark, Squalus acanthias

We investigated the steroid biosynthetic capabilities of ovarian granulosa and thecal elements of the viviparous dogfish, Squalus acanthias. In this report we present evidence that granulosa cells secrete quantitatively important amounts of progesterone (P), testosterone (T), and estradiol-17 beta (E), while theca has a more limited capacity to synthesize T and E. Ovarian granulosa cells were obtained from animals at each stage of gestation. After collagenase dispersion, an aliquot of 250,000 cells was incubated at 18 degrees C in basal medium, containing Eagle's salts, glutamine, penicillin, streptomycin and adjusted with 136 mM sodium chloride and 350 mM urea. After a 4 hour incubation, the content of P, T, and E in medium was determined by radioimmunoassay. P was not detectable at any time, while E was present throughout the cycle, being maximal when gestation is three quarters complete (Stage C). T gradually increased from Stage B toward late pregnancy. In Stage C granulosa cells, E production increased in the presence of graded doses of T substrate. Also, a homologous pituitary extract (1/25 equivalents) and the calcium ionophore A23187 stimulated production of all 3 steroids. Using radioisotopes, granulosa cells showed a wide range of synthetic capacities. In Stage C thecal tissue, E production also increased in the presence of graded doses of T substrate, while pituitary extract only increased T. When granulosa and theca were recombined, in the presence of pituitary extract, P levels decreased with a corresponding increase in T, when compared to granulosa alone. These data suggest a possible interaction between granulosa and theca for steroid biosynthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of steroid and steroid sulfate production and aromatase activity in cultured human granulosa-luteal cells

The regulation of the production of steroids and steroid sulfates and the activity of aromatase in human luteinized granulosa cells were investigated. The cells were cultured for 48 h in the presence or absence of hCG and FSH. Basal production of pregnenolone (Pre, 0.3 +/- 0.03 ng/micrograms protein) and progesterone (P, 19.3 +/- 1.7 ng/micrograms protein) were high compared with that of other steroids beyond P in the steroidogenic pathway. The concentration of 17 alpha-hydroxyprogesterone (17-OHP) was lower 0.17 +/- 0.06 ng/micrograms and that of other steroids in the 4-ene and 5-ene pathways and steroid sulfates less than 0.05 ng/micrograms. Both hCG and FSH (100 ng/ml) stimulated the production of Pre and P 3- to 5-fold, but only minimal stimulation of other steroids and steroid sulfates was observed. Aromatase activity of granulosa-luteal cells was measured from the rate of formation of 3H2O from 1 beta-[3H]androstenedione (1 beta[3H]A) after exposing the cells to hCG, FSH or estradiol (E2) for 48 h. Basal aromatase activity was relatively low, but hCG and FSH stimulated aromatase 8- and 4-fold, respectively. The incubation of granulosa-luteal cells with E2 did not affect basal aromatase activity, but E2 augmented FSH-stimulated aromatase 1.4-fold (P less than 0.025). The results suggest that there is low 17 alpha-hydroxylase and steroid sulfokinase activity in human granulosa-luteal cells. Aromatase activity in these cells is regulated by both hCG and FSH, and intra-ovarian estrogens may regulate granulosa cell aromatase activity.

In vitro fertilization as a diagnostic and therapeutic tool in a patient with partial 17,20-desmolase deficiency

OBJECTIVE

To present a case with 17,20-desmolase activity deficiency in which in vitro fertilization (IVF) served not only as a therapeutic approach but also as a diagnostic tool for the specificity of the enzymatic deficiency.

DESIGN

IVF in the patient under study compared with a control group. All women treated with pure follicle-stimulating hormone (FSH).

SETTING

IVF program at the Instituto Valenciano de Infertilidad.

PATIENTS, PARTICIPANTS

A patient with primary amenorrhea, who was the subject under study, and seven normally cycling control patients undergoing IVF in the same series.

INTERVENTIONS

IVF, steroidogenesis in vitro of granulosa-luteal cell obtained at ovum pick-up.

MAIN OUTCOME MEASURE(S)

Oocyte fertilization and embryo cleavage. Serum and follicular fluid (FF) levels of estradiol (E2), progesterone (P), testosterone (T), androstendione (A), 17 alpha-hydroxyprogesterone (17-OHP). In vitro accumulation of E2 and P.

RESULTS

Ovulation induction with FSH was successful in achieving follicular development despite low circulating E2. Fertilization and cleavage rates were similar to the control subjects. The patient developed ovarian hyperstimulation. The lack of 17,20-desmolase activity was detected by normal P levels in serum and FF, high 17-OHP, and low T, A, and E2 levels in serum and FF. Granulosaluteal cell cultures in the presence of T restored normal E2 and P production in response to gonadotropins.

CONCLUSIONS

In patients with 17,20-desmolase deficiency, follicular development, oocyte maturation, and fertilization can take place in a low estrogenic environment.

Oestrogens inhibit steroid production by dispersed porcine thecal cells

An intra-ovarian role for oestrogens in the control of steroid production was investigated using dispersed thecal cells obtained from porcine follicles. Thecal cells were incubated for 14 h at 37 degrees C and the media subsequently assayed for androstenedione, progesterone and cyclic AMP. LH caused a dose-dependent stimulation of both steroids and the addition of oestradiol at doses of 10 ng-10 micrograms/ml significantly (P less than 0.01) inhibited both basal and LH-stimulated steroid production from doses of 500 ng/ml and upwards. Of other oestrogens investigated, oestrone and oestriol were somewhat less potent than oestradiol in inhibiting steroid synthesis, whereas the synthetic oestrogen diethylstilbestrol (DES) was more potent. The presence of oestradiol at doses of 10 ng-10 micrograms/ml had no significant effect (P less than 0.05) on either basal or LH-stimulated cAMP suggesting that the oestradiol inhibition does not involve inhibition of LH receptor-linked adenylate cyclase. These results demonstrate that physiological doses of oestrogen can act by local negative feedback to control the synthesis of its own precursor and thus regulate intrafollicular steroidogenesis.

The effect of follicular fluid protein(s) on gonadotropin-modulated secretion of progesterone in porcine granulosa cell cultures

Porcine granulosa cells from medium-sized follicles (2 to 5 mm in diameter) were cultured (100,000 cells per culture) with various concentrations of a 12,500 to 16,000 molecular weight protein fraction isolated from follicular fluid. To these cultures pregnenolone (10(-5) mol/L) and either human chorionic gonadotropin or porcine follicle-stimulating hormone were added. The conversion of pregnenolone to progesterone was used to determine 3-beta-ol-dehydrogenase activity in the granulosa cells. Follicular fluid protein alone caused a biphasic response in the production of progesterone. Follicular fluid protein in the concentration of 167 micrograms/ml caused a tenfold increase in the production of progesterone, whereas the 500 micrograms/ml concentration caused a return to baseline levels. Although porcine follicle-stimulating hormone induced a dose-response increase in the production of progesterone, human chorionic gonadotropin produced no change in the levels of progesterone. Low doses of follicular fluid protein acted synergistically with low doses of porcine follicle-stimulating hormone to increase granulosa cell secretion of progesterone. However, high doses of follicular fluid protein inhibited the low-dose stimulation by porcine follicle-stimulating hormone of the production of progesterone. High doses of porcine follicle-stimulating hormone (10 microgram/culture) overcame both the low-dose enhancement and the high-dose inhibition of follicular fluid protein on granulosa cell secretion of progesterone. Thus follicular fluid protein may be an important paracrine modulator of steroidogenesis stimulated by follicle-stimulating hormone in the porcine granulosa cell.

Steroidogenic capabilities of various compartments of rat ovarian follicles in culture

The production of progesterone, estrogen and androgen as well as the metabolism of radiolabelled progesterone by various cellular components of rat ovarian follicles were studied. Granulosa (G), theca (T), recombined granulosa plus theca (G+T) and intact follicular wall (FW) of ovaries from immature rats treated with pregnant mare serum gonadotropin (8 IU) were cultured for 24 h in the presence or absence of [4-14C]progesterone. The estrogen and androgen accumulation when calculated per follicle was several fold greater in FW than in G, T, or G+T preparations. The conversion of radiolabelled progesterone to its identified C21 catabolites (20 alpha-hydroxy-4-pregnen-3-one and 3 alpha-hydroxy-5 alpha-pregnan-20-one) was significantly lower in FW than in G+T incubations. Conversely, the metabolism of radiolabelled progesterone to androsterone was several fold greater in FW than in G+T incubations. Addition of hydroxyflutamide to FW incubations significantly decreased estrogen production and increased the conversion of radiolabelled progesterone to androsterone. Estrogen production by follicular wall may be enhanced by androgenic stimulation of aromatase activity as well as by a structure-dependent factor(s) of a yet unknown nature, both of which may decrease progesterone catabolism to biologically inactive progestins while promoting progesterone conversion to androgens and eventually to estrogens.

Formation of androgen conjugates by porcine granulosa cells

The relative abilities of isolated and recombined theca and granulosa cells, derived from medium-sized porcine ovarian follicles, to synthesize androgens and estrogens were compared. Isolated thecal preparations produced large amounts of immunoreactive androstenedione and testosterone. When theca was co-cultured with granulosa cells, accumulation of both these androgens was markedly less. Though the co-cultures produced significantly higher amounts of estradiol, this increase did not account for the reduced androgen production. To determine if the lesser androgen accumulation in the combined cultures was due to metabolism by granulosa cells of androgens to other metabolites, the fate of [3H]androstenedione or [3H]testosterone was followed. Whenever granulosa cells were present in the incubation dishes, most of the radioactivity remained in the aqueous fraction after ether extraction. Examination of the aqueous fraction by DEAE-Sephadex A25 demonstrated the presence of androgen sulphates. The results suggest that granulosa cells are the site at which follicular formation of androgen sulphates takes place.

Steroids in porcine follicular fluid: analysis by HPLC, capillary CG and capillary CG/MS after purification on SEP-PAK C18 and ion exchange chromatography

Steroids in porcine follicular fluid have been concentrated by reverse phase chromatography in SEP-PAK C18 and purified further on the cation exchanger SP-Sephadex C-25. Fractionation into unconjugated neutral and phenolic steroids, glucuronides and sulfates was carried out on triethylaminohydroxypropyl Sephadex LH-20 (TEAP-LH-20). The unconjugated neutral fraction was analysed by high pressure liquid chromatography (HPLC) on a C18 radial cartridge 5 mm I.D.; 10 mu, or on a C18 5 mu RESOLVE column, and by capillary gas chromatography (GC) on a 12 M OV-1 cross linked fused silica column. Testosterone, progesterone and androstenedione were the major steroids detected by HPLC monitored at 254 nm, although 17- hydroxy-, 20 alpha-dihydro- and 20 beta-dihydroprogesterone were also present. Pregnenolone, pregnanediol, dehydroepiandrosterone, 17-hydroxypregnenolone and androsterone were detected by capillary CG as their 0-methyloxime trimethylsilyether derivatives. Further confirmation of structure was provided by complete mass spectral data or by selective ion monitoring (SIM).

Granulosa theca cell tumors in premenarchal girls: a clinical and pathologic study of ten cases

Granulosa theca cell tumor (GTCT) in the premenarche accounted for 7% of all ovarian tumors treated at the Children's Hospital Medical Center from 1928 through 1979. The average age of the ten girls at the time of diagnosis was 5 years (range 11 months-121/2 years) with precocious "pseudopuberty" and an abdominal mass being the most common presentation. GTCTs were solitary (five right, five left) with an average diameter of 12.1 cm. Histologic examination showed a predominantly diffuse or solid pattern with prominent luteinization; Call-Exner bodies and folded ("coffee-bean") nuclei were inconspicuous. Ultrastructural examination of one GTCT confirmed the presence of both granulosa and theca components with the latter showing extensive luteinization; estradiol, testosterone and prolactin were demonstrated in the same tumor using immunologic techniques. The average follow-up time was 21 years with nine of the ten patients being followed for more than ten years. Salpingo-oophorectomy resulted in cures despite the occurrence of tumor spillage in two patients. The prognosis for GTCTs in the premenarche appears more favorable than for those occurring in adulthood, but further study is needed to completely define their full biologic potential; the significance of subsequent breast cancer in two long-term survivors merits further investigation as well.

The source of follicular androgens in the hamster follicle

The comparative ability of granulosa cells and theca of the hamster preovulatory follicle to produce androgens in vitro from endogenous and exogenous substrates was assessed. The results indicate that theca are the major source of follicular androstenedione, but that the granulosa cells may be the major source of follicular testosterone. Theca and granulosa cells accumulate comparable amounts of dihydrotestosterone from exogenous androstenedione and testosterone and both may be a significant source of follicular DHT. LH stimulates the conversion of progesterone and 17 alpha-OH progesterone to androstenedione, testosterone and DHT in theca. LH does not stimulate the conversion of androstenedione to testosterone or DHT, and that of testosterone to DHT in either granulosa cells or theca. FSH, in granulosa cells but not in theca, stimulates the conversion of adrostenedione to testosterone but it has no effect in DHT accumulation from exogenous testosterone.

Effects of follicular development on the ability of cultured porcine granulosa cells to convert androgens to estrogens

Porcine granulosa cells from different stages of follicular development were examined for their ability to convert androgens to estrogens and their ability to secrete progesterone. Granulosa cells from all stages of follicular development can convert androgens to estrogens, and the addition of exogenous androgen is required for estrogen secretion. Granulosa cells obtained from medium and large follicles have a greater capacity to convert androgens to estrogens than do granulosa cells obtained from small follicles. The addition of FSH brought about an increase in estrogen secretion in the presence of androgen only in granulosa cells from large follicles. LH attenuated estrogen secretion in granulosa cells from medium follicles treated with testosterone. Granulosa cells from medium follicles were unable to secrete estrogen from days two to four irrespective of treatment. Androgens augment FSH stimulated progesterone secretion in granulosa cells from medium follicles from days two to four, and the addition of follicular fluid from small follicles stimulates progesterone secretion in the presence of FSH and androgens.

Aromatase activity of isolated and recombined hamster granulosa cells and theca

The major synthesis of estrogen by the follicle is postulated to require both theca and granulosa cells. Theca in this scheme provide androgens to the major aromatizing site in the follicle, and the granulosa cell. One aspect of this theory was tested here. We investigated the comparative ability of isolated granulosa and theca, alone and in recombination to aromatize androgen in vitro. We found that the granulosa aromatize [14C]substrate more efficiently than do theca, and compare with the recombined system in their ability to aromatize [14C]androgen. The data therefore substantiates one aspect of the theory regarding the nature of the synergism, i.e., that the granulosa cells, at least in vitro, are the major site of aromatization of the preovulatory follicle.

Evidence for interaction between granulosa cells and theca in early progesterone synthesis

The temporal characteristics of steroidogenesis in vitro by hamster preovulatory follicles, were compared to granulosa cells and theca incubated separately. Gonadotropin-stimulated intact follicles or recombined granulosa cells and theca synthesized increased amounts of progesterone by 30-120 minutes of incubation. The granulosa cells and theca, when incubated separately, did not begin to accumulate progesterone until 4 to 6 hours. The relatively rapid rise in follicular progesterone synthesis after in vitro gonadotropin stimulation follows the same time course as the rapid rise in vivo of hamster and rat preovulatory progesterone after the gonadotropin surge. The sharp differences in the temporal characteristics of progesterone synthesis between follicles and separated follicular cell types suggest an interaction between granulosa cells and theca in at least one phase of progesterone synthesis.

Enzyme histochemistry of cultured ovarian cells. I. Histochemistry of porcine preovulatory granulosa cells in culture

Histochemical activity of hydroxysteroid dehydrogenases as well as alkaline and acid phosphatase was investigated in porcine granulosa cells cultured in vitro. Granulosa cells, isolated from preovulatory procine ovarian follicles, during in vitro culture showed activity of enzymes participating in steroid biosynthesis. High activity of delta53betta0H-SDH and G6P-DH as well as the activity of alkaline phosphatase, appearing in the course of culture, could be evidence of progressive luteinization of the cells. Activity of 17beta0H-SDH was lower and exhibited strong fluctuations, similarly low was 20xOH-SDH. Gonadotropic hormones caused the increase of synthesis and accumulation of intracellular lipids. They stimulated alkaline and acid phosphatase, and also the activity of the dehydrogenases. LH had the most visible effect. Estradiol stimulated the activity of acid but not alkaline phosphatase and was not influencing, even lowering the activity of dehydrogenases.