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PubMed1999

Role of ovarian theca and granulosa cell interaction in hormone productionand cell growth during the bovine follicular maturation process.

We have investigated the possible role of theca and granulosa cell interaction in the control of the hormone-producing activity and growth of granulosa and theca cells during bovine ovarian follicular development, using a coculture system in which granulosa and theca cells were grown on opposite sides of a collagen membrane. When follicular cells were isolated from small follicles (3-5 mm), theca cells reduced estradiol, progesterone, and inhibin production by granulosa cells to 14 +/- 5%, 64 +/- 6%, and 27 +/- 4%, respectively, of the production by granulosa cells cultured alone. On the other hand, when the cells were isolated from large follicles (15-18 mm), theca cells increased these levels to 253 +/- 34%, 156 +/- 24%, and 287 +/- 45%, respectively. Theca cells did not affect the growth of granulosa cells. Androstenedione production by theca cells was augmented by granulosa cells to 861 +/- 190% (in small follicles) and 1298 +/- 414% (in large follicles), respectively. The growth of theca cells was also augmented by granulosa cells (small follicle, 210 +/- 43%, and large follicle, 194 +/- 24%, respectively). These results indicate that theca cells secrete factor(s) inhibiting the differentiation of immature while promoting that of matured granulosa cells; they also suggest that granulosa cells secrete factor(s) promoting both the differentiation and growth of theca cells throughout the follicular maturation process.

Androstenedione↗
PubMed1993

Evolution of prothymosin alpha and proliferating cell nuclear antigen (PCNA) immunoreactivity through the development of rat ovarian follicles.

The cellular distribution of prothymosin alpha (ProT) was studied in ovarian follicles of adult cycling rats. We found positive granulosa and theca cells throughout follicular maturation. When both ProT and proliferating cell nuclear antigen (PCNA) immunoreactivity was studied, we observed that both proteins were expressed in the same granulosa and theca cells, although sometimes ProT immunoreactivity was weak or absent in the mitotic (M) phase. Moreover, both peptides share the nuclear distribution, but ProT immunoreactivity was never seen in nucleoli. Therefore, we conclude that in mitotic cells ProT is expressed only in actively proliferating cells, since all ProT-positive cells were also positive for PCNA. ProT and PCNA immunoreactivities during the meiotic division were studied in oocytes. The presence of PCNA was, unlike ProT, constant throughout follicle development (except atretic oocytes). Oocytes expressed ProT from primordial follicles to the eighth generation, but more developed oocytes and atretic oocytes were not immunoreactive. In hypophysectomized rats, all oocytes were immunoreactive. Interestingly, in hypophysectomized rats treated with follicle stimulating hormone (FSH) that promoted follicle development, the more developed oocytes did not show ProT immunoreactivity. Since hypophysectomized rats were not treated with luteinizing hormone we conclude that ProT expression is not required to complete meiotic division I.

Animals↗
PubMed2006

Immunohistochemical localization of proliferating cell nuclear antigen (PCNA) in the pig ovary.

The aim of the study was to determine the expression of proliferating cell nuclear antigen protein (PCNA) in the pig ovary. The localization of PCNA was demonstrated in paraffin sections of pig ovarian tissue using primary mouse monoclonal anti-PCNA antibody. In primordial follicles, no remarkable staining for PCNA either in granulosa cells or in the oocytes was observed. In primary to secondary follicles, positive staining in oocytes and in some granulosa cells was detected. The advanced preantral and particularly actively growing small to large antral follicles showed extensive PCNA labeling in the layers of granulosa and theca cells and in the cumulus cells encircling the oocyte. PCNA labeling was expressed in nuclei of oocytes in preantral and small antral follicles. In atretic follicles, the level of PCNA protein expression was dependent on the stage of atresia. Follicles demonstrating advanced atresia showed only limited or no PCNA labeled granulosa and theca cells. The results of the study demonstrate that follicular growth and development in pig ovary may be effectively monitored by determining the granulosa cell expression of PCNA.

Animals↗
PubMed2001

Developmental gonadal expression of the transcription factor SET and its target gene, P450c17 (17alpha-hydroxylase/c17,20 lyase).

Cytochrome P450c17 catalyzes the 17alpha-hydroxylase/17,20 lyase activity needed for sex steroid synthesis. We recently characterized the nuclear phosphoprotein SET as a novel transcriptional regulator that binds to the -447/-399 region of the rat P450c17 gene, along with the transcription factors COUP-TF II, NGF-IB, and SF-1. Gel shift studies localized SET binding to nucleotides -410/-402. We have shown that SET activates transcription of the rat P450c17 gene in neuronal precursor cells and now show that it also activates transcription from the -418/-399 region of the rat P450c17 gene in mouse Leydig MA-10 cells. Studying the ontogenic expression of SET and P450c17 in the rodent gonad, we found that SET expression preceded P450c17 expression in the embryonic genital ridge, suggesting that SET may be important for initiating P450c17 expression in this region. Expression of SET also preceded P450c17 expression in the testis and ovary, and its expression was much greater during embryogenesis than in the adult gonad. In the adult rat testis, P450c17 was expressed only in Leydig cells, while SET was expressed in Leydig cells and in spermatocytes. In the adult rat ovary, P450c17 was expressed only in theca cells, while SET was expressed in theca cells and also in oocytes. Because SET is expressed early in development in the genital ridge and in the testis and ovary, and because SET has many functions in addition to its activity as a transcription factor, we determined whether SET acts a transcription factor in oocytes. The SET protein was detected by Western blots in Xenopus oocytes from stages II through VI and in mature oocytes. Using extracts of Xenopus oocytes in gel shift assays, we detected a protein that bound to the -418/-399 region of the rat P450c17 gene, to which SET binds. Nuclear injection of either a -418/-399TK32LUC wildtype reporter construct or a construct containing a mutant SET site into Xenopus oocytes from stages III through VI resulted in activation of luciferase activity with the wildtype but not the mutant construct in all stages. These data suggest that Xenopus SET is able to bind to specific DNA sequences to activate transcription at all stages of Xenopus oogenesis. These data indicate that SET is an evolutionarily conserved transcription factor that participates in the early ontogenesis of the gonadal system, regulates P450c17 gene transcription in Leydig cells, and may also activate other genes expressed in immature oocytes, thus playing a role in oocyte development.

Animals↗
PubMed1998

Presence of transforming growth factor alpha and epidermal growth factor in human ovarian tissue and follicular fluid.

Intra-ovarian regulation of follicular maturation is modulated by various factors. Among these, growth factors are important local actors. We examined the immunohistochemical localization of transforming growth factor alpha (TGF-alpha), epidermal growth factor (EGF) and epidermal growth factor receptor (EGF-R) in 18 human ovaries. The concentration of TGF-alpha and EGF in follicular fluid was measured by ELISA. TGF-alpha was detected in oocytes of primordial and early preantral follicles. Furthermore, staining was observed in granulosa cells of preantral follicles and in theca cells of preantral, antral and preovulatory follicles. EGF showed a similar distribution as TGF-alpha. Atretic follicles were strongly positive for TGF-alpha and EGF. In the corpus luteum, theca lutein cells were strongly positive for TGF-alpha and EGF. Immunoreactivity for EGF-R was observed only in the granulosa cells of antral follicles. Follicular fluids from patients undergoing in-vitro fertilization (IVF) were examined for their content of TGF-alpha and EGF. TGF-alpha was detected in 37% of the samples. The concentration ranged from 43 pg/ml to 602 pg/ml. EGF was not detected in any of the follicular fluids tested. These observations support the participation of EGF/TGF-alpha in follicular maturation. Furthermore, the presence of TGF-alpha in follicular fluid and the simultaneous absence of EGF suggests that TGF-alpha plays a more pronounced role than EGF in oocyte maturation during late follicular phase.

Adolescent↗
PubMed2000

Time dependent and cell-specific action of polychlorinated biphenyls (PCB 153 and PCB 126) on steroid secretion by porcine theca and granulosa cells in mono- and co-culture.

To characterize PCB action on follicular cell steroidogenesis two PCB congeners were selected as model substances. PCB 126 because of its dioxin-like configuration and high toxicity and PCB 153 because it is one of the most commonly detected PCB congeners in breast milk. The direct effect of PCBs was investigated using a culture system of porcine theca and granulosa cells collected from porcine preovulatory follicles. Granulosa and theca cells were cultured in M199 medium supplemented with 1, 10 or 100 pg/ml of PCB 126 or 1, 10 and 100 ng/ml of PCB 153. The media were changed after 48, 96 and 144 h and frozen until further estradiol (E2) analysis. Additionally, progesterone (P4) was measured in the granulosa cells culture medium and testosterone (T) in theca cells culture medium. Decrease of testosterone concentration in the theca cells culture medium was found after 96 and 144 hours in culture by both investigated PCB congeners. A decrease in E2 concentration was found after exposure to PCB 153. These findings suggest different actions of two congeners on the steroid synthesis in theca cells. The lack of an increase in E2 secretion after the exposure to PCB 126 could be due to depletion of androgen precursor. In granulosa cell culture PCB153 decreased E2 secretion and increased P4 secretion suggesting luteinization and disruption of aromatization process. PCB 126 in a doses from 1 to 10 pg had no effect on granulosa cells steroidogenesis. However, the highest dose (100 pg) increased concentration of both E2 and P4. This observation suggest that PCB 126 in a pharmacological doses may affect cell membrane permeability, thereby increasing steroid outflow into the medium. These results suggest time dependent and cell-specific differences in PCB 153 and 126 action on follicular cells steroidogenesis. Further studies are required to elucidate the mechanism of PCBs action on ovarian steroidogenesis.

Animals↗
PubMed1976

Hormonal function of a granulosa cell tumor.

Granulosa and theca cell tumors are rather common gonadal stromal tumors. A postmenopausal patient with a granulosa cell tumor, who complained chiefly of breast tenderness and enlarging, abdomen, is presented. Preoperative and postoperative studies including serum estrone, estradiol, prolactin, FSH, and LH,as well as urinary estrogens, 17-ketosteroids, and 17-hydroxysteroids are reported. A plan of treatment and followup is suggested. It is recommended that survival data on patients with such slow-growing tumors be adjusted to reflect the true incidence of death from the specific tumor in question.

Aged↗
PubMed1997

[Expression of transforming growth factor-alpha and myc oncoprotein in the human ovary during follicular growth, atresia and corpus luteum formation regression].

OBJECTIVE: To investigate the expression of transforming growth factor (TGF)-alpha and myc oncoprotein on human follicular development and atresia in vitro. METHODS: Ovarian tissues were obtained from 36 women with regular menstrual cycles who underwent abdominal hysterectomy for a variety of gynecological conditions. Expression of TGF-alpha and myc protein in the ovarian tissues was examined by immunohistochemical technique. RESULTS: In primordial follicale only the oocyte showed intense immunostaining for both TGF-alpha and myc oncoprotein. Immunostaining for TGF-alpha in granulosa cells and theca interna cells became apparent in the follicles of preantral stage. With the increase in the size of follicles the intensity of immunostaining in the oocyte decreased, whereas the staining intensity of the granulosa and theca cells increased, and persisted in the corpus luteum and further intensifying during the midluteal phase. myc protein expression in granulosa cells was apparent only in the preantral follicle stage. In the regressing corpus luteum, expression of both TGF-alpha and myc oncoprotein was restricted only in the peripheral theca lutein cells adjacent to the central core of scar issue. In atretic follicles theca interna cells exhibited prominent immunostaining for TGF-alpha and myc protein. CONCLUSION: TGF-alpha and myc oncoprotein combination play a role as intraovarian regulators through autocrine and paracrine mechanism and may participate in remodelling the initial growth of the oocyte, follicular growth, differentiate and apoptosis.

Adult↗
PubMed2003

Expression of messenger RNA for ADAMTS subtypes changes in the periovulatory follicle after the gonadotropin surge and during luteal development and regression in cattle.

Extensive remodeling of the extracellular matrix occurs in the ovary during the periovulatory period. Matrix metalloproteinases and their endogenous inhibitors, tissue inhibitors of metalloproteinases, are believed to play integral roles in this highly regulated series of cellular events, but their specific roles remain unclear. Recent cloning studies have identified a novel family of metalloproteinases, the ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) family. The regulated expression of distinct ADAMTS subtypes has been shown to be required for tissue morphogenesis during embryonic development and for maintaining the integrity of tissues in the adult. In the present studies, we have determined that multiple ADAMTS subtypes are present in the bovine ovary using a reverse transcription-polymerase chain reaction strategy. In particular, ADAMTS-1, -2, -3, -4, -5 (also known as ADAMTS-11), -7, -8, and -9, but not ADAMTS-6, -10, or -12, mRNA transcripts were detected in granulosa cells of nonatretic ovarian follicles and corpora lutea. The levels of mRNA for these ovarian ADAMTS were up- or down-regulated or remained unchanged in the granulosa and/or theca cells of the dominant follicle following the preovulatory surge of gonadotropins, depending on the subtype and/or the cell compartment, and in the corpus luteum during the luteal phase of the estrous cycle. The complex expression patterns observed for the distinct ADAMTS subtypes in the granulosa and theca cells of the periovulatory follicle and in the luteal tissues of the bovine ovary suggest that these novel proteases mediate, at least in part, the remodeling events underlying folliculogenesis and ovulation and the formation, maintenance, and regression of the corpus luteum.

Animals↗
PubMed1988

Antibiotic-associated inhibition of steroidogenesis during short-term culture of ovarian tissues of the domestic fowl.

The effects of antibiotics on bovine luteinizing hormone (bLH)-stimulated output of androstenedione were examined in intact small white follicles (SWF, n = six hens), aliquots of 100,000 F1 and F2 theca cells (n = six hens), and aliquots of 10,000 F1 and F2 granulosa cells (n = eight hens). Cells and SWF were isolated from ovaries of Leghorn hens killed 20 h prior to ovulation and were incubated for 3 h in 1 mL of Medium 199 (Sigma Chemical Co., St. Louis, MO) at 37 C. Cells and follicles were incubated with 10 ng bLH and Penicillin-streptomycin (Pen-Strep; 20, 100, and 200 micrograms), gentamicin sulfate (gentamicin; 10, 50, and 100 micrograms), and fungizone (.5, 2.5, and 5.0 micrograms). Two control treatments consisted of tissues incubated alone (no bLH, no antibiotic) and tissues incubated with 10 ng bLH (no antibiotic). Androstenedione output by SWF and F1 and F2 theca cells and progesterone output by F1 and F2 granulosa cells were determined by radioimmunoassay of incubation media. The steroid contents of the incubation media were significantly increased in SWF and theca and granulosa cells with the addition of bLH. Neither Pen-Strep nor gentamicin significantly affected steroid output. Progesterone output by F1 and F2 granulosa cells was significantly reduced by the inclusion of fungizone. The inhibition of steroid output with the use of fungizone should be considered when using this antibiotic in studies of steroidogenesis in preparations of ovarian cells.

Amphotericin B↗
PubMed1989

Identification of 3-deoxy-manno-2-octulosonic acid, 3-deoxy-5-O-methyl-manno-2-octulosonic acid and 3-deoxy-lyxo-2-heptulosaric acid in the cell wall (theca) of the green alga Tetraselmis striata Butcher (Prasinophyceae).

The main constituent of the cell wall complex carbohydrate of the scaly green alga Tetraselmis striata Butcher is shown to be 3-deoxy-manno-2-octulosonic acid (42%). In addition two other 2-keto-sugar acids are present, namely, 3-deoxy-5-O-methyl-manno-2-octulosonic acid (7%), the first methylated derivative of 3-deoxy-manno-2-octulosonic acid found in nature, and 3-deoxy-lyxo-2-heptulosaric acid (11%). The characterization of the three 2-keto-sugar acids has been carried out on the corresponding methyl ester methyl glycosides using GLC-MS and 500-MHz 1H-NMR spectroscopy, and on the corresponding reduced alditol acetates using GLC-MS. Other monosaccharides occurring in the cell wall are D-galacturonic acid (14%), D-galactose (4%), D-gulose (2%), D-glucose (1%) and L-arabinose (1%).

Cell Wall↗
PubMed2006

Hormonal regulation and differential expression of neuropilin (NRP)-1 and NRP-2 genes in bovine granulosa cells.

Although much is known about the biology of vascular endothelial growth factor (VEGF) and its receptors, little is known about the role of the VEGF receptors neuropilin (NRP)-1 and NRP-2 in the process of bovine follicle development. The aim of the present study was to examine the hormonal regulation of NRP-1 and NRP-2 mRNAs by real-time PCR in follicles from the bovine ovary and in cultured granulosa cells. The NRP-1 gene was expressed in the granulosa and theca cells in the post-selection (POF) and pre-selection (PRF) follicles in the bovine ovary. In contrast, the NRP-2 gene was expressed only in the theca cells in the POF and the PRF. The level of NRP-1 mRNA was significantly increased by treatment of the cultured granulosa cells with 10 ng/ml estradiol (E2). In contrast, the addition of progesterone (P4) to the culture medium decreased the expression of the NRP-1 gene. The level of NRP-1 mRNA was increased by 10 ng/ml E2 with or without 1 ng/ml P4, but the level of NRP-1 mRNA was decreased if the P4 level was increased to 10 ng/ml, even when 1 ng/ml E2 was also added. Follicle-stimulating hormone did not stimulate the expression of the NRP-1 gene. These results are the first data showing that NRP-1, but not NRP-2, is expressed in the granulosa cells of bovine follicles and that NRP-1 gene expression is regulated by sex steroids. Our findings suggest the involvement of NRP-1 in follicle development in the cow.

Animals↗
PubMed1997

Fibroblast growth factor receptor (FGFR)-4, but not FGFR-3 is expressed in the pregnant ovary.

The intraovarian mechanisms for follicle recruitment, growth, maturation, and ovulation are not well understood. The data suggest that fibroblast growth factor (FGF)-2 is expressed in granulosa and theca cells of growing and mature follicles and in luteal cells during pregnancy. Exogenous FGF-2 modulates steroidogenesis, stimulates tissue plasminogen activator (tPA), and induces germinal vesicle breakdown (GVBD) in cultured follicles. Previously, we have reported that another FGF ligand, FGF-4, is expressed in ovulated mouse oocytes. Two studies have examined the expression of receptors (FGFR) for FGF ligands in the ovary. These prior reports have been limited to FGFR-1, one of the four isoforms that are variably expressed in adult mammalian tissues. This study evaluates FGFR-4 and FGFR-3 mRNA expression in the ovary. Granulosa cells from several follicular stages express the receptor for FGFR-4 mRNA as assayed by in situ hybridization. FGFR-4 mRNA is not expressed in theca cells or the oocyte. FGFR-3 mRNA is not detected in the ovary by in situ hybridization. These results suggest that FGFR-4 may play a role in mediating the effects of FGF ligands in follicular development in the ovary.

Animals↗
PubMed1995

Quantitative evaluation of the cell cycle-related retinoblastoma protein and localization of Thy-1 differentiation protein and macrophages during follicular development and atresia, and in human corpora lutea.

Ovarian follicular development is dependent on growth and differentiation of the oocyte, as well as the granulosa and theca cell layers. The majority of primary follicles in the adult human ovary are not growing, and most antral follicles undergo atresia. The mechanisms regulating follicular growth and differentiation are poorly understood. Expression of key regulatory proteins in cells of certain follicles may be involved. We have studied the distribution of retinoblastoma protein (pRb), a key cell cycle regulator, in human follicles and CL by quantitative immunohistochemistry. Recent studies suggest that high nuclear concentrations of pRb are associated with the arrest of cell proliferation and the beginning of differentiation; during advanced differentiation of cells pRb is markedly depleted or absent. We also studied follicular distribution of Thy-1 differentiation protein, a morpho-regulatory molecule associated with cell differentiation, and the presence of macrophages. Macrophages have been shown to stimulate steroidogenesis in granulosa cells in vitro, and they are required for release of Thy-1 differentiation protein from vascular pericytes among granulosa cells in vivo. Our results indicate that oocytes in resting follicles exhibit pRb in the nucleoli. During initiation of follicular growth, the pRb expression first extends over the oocyte nuclei and then diminishes from both nuclei and nucleoli in preantral follicles. When the oocytes reach maximum size in small antral follicles, the pRb expression is reestablished in oocyte nucleoli. In differentiating granulosa and theca cell layers of preantral and small antral follicles, pRb expression is high, but it is low in growing large antral follicles. During CL development and regression, pRb expression in the nuclei of granulosa lutein cells first increases and then decreases. Follicular development is accompanied by the presence of Thy-1 differentiation protein and macrophages under the follicular basement membrane. In growing large antral follicles, during the mid-follicular phase, larger macrophages exhibit physical contacts with granulosa cells through the follicular basement membrane, and, during the late follicular phase, small dendritic macrophages can be detected among granulosa cells, but not within the follicular antrum. Large antral follicles undergoing atresia exhibit strong pRb expression in granulosa cells. This is accompanied by a lack of Thy-1 differentiation protein among granulosa cells and the occurrence of large phagocytic macrophages in the follicular antrum. This is the first report of pRb expression in the human ovary.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Cycle↗
PubMed2002

Effect of preantral follicle isolation technique on in-vitro follicular growth, oocyte maturation and embryo development in mice.

BACKGROUND: The use of mechanical and enzymatic techniques to isolate preantral follicles before in-vitro culture has been previously described. The aim of this study was to assess the effect of the isolation procedure of mouse preantral follicles on their subsequent development in vitro. METHODS: Follicles were isolated either mechanically or enzymatically and cultured using an individual non-spherical culture system. Follicular development and steroidogenesis, oocyte in-vitro maturation and embryo development were assessed for both groups. RESULTS: After 12 days of culture, follicles isolated mechanically had a higher survival rate but a lower antral-like cavity formation rate than follicles isolated enzymatically. Enzymatic follicle isolation was associated with a higher production of testosterone and estradiol compared with mechanical isolation. A stronger phosphatase alkaline reaction was observed after enzymatic isolation, suggesting that follicles isolated enzymatically had more theca cells than those isolated mechanically. However, both isolation techniques resulted in similar oocyte maturation and embryo development rates. CONCLUSIONS: Enzymatic follicular isolation did not affect theca cell development. Follicular steroidogenesis was enhanced after enzymatic isolation but the developmental capacity of oocytes was comparable to that obtained after mechanical isolation.

Animals↗
PubMed1998

The pathogenesis of polycystic ovary syndrome: lessons from ovarian stimulation studies.

In polycystic ovary syndrome (PCOS) the ovary produces markedly increased amounts of both androgens and estrogens in response to gonadotropin stimulation. Distinctive responses of 17-hydroxyprogesterone and androstenedione to ovarian stimulation testing suggest that ovarian hyperandrogenism is a result of dysregulation of theca cell androgen production which is intrinsic to the ovary. The occurrence of hyperestrogenism together with hyperandrogenism in PCOS suggests that whatever the abnormality of local regulatory factors of steroidogenesis, it affects granulosa as well as theca cells. Dysregulation is often associated with an increase in the number of follicles which evade atresia and reach the 2-8 mm stage of development. Autocrine/paracrine factors, especially those which are FSH-dependent, likely play an important role in the pathogenesis of the ovarian abnormality. Both LH and insulin hypersecretion probably play a secondary role in PCOS by amplifying the preexisting ovarian dysregulation. Because FSH secretion is under tight long-loop negative-feedback control and LH is not, hyperandrogenism is the primary clinical manifestation of dysregulation of steroid production in PCOS. However, anovulation in PCOS is most likely a result of excessive estrogen and inhibin production by multiple, small follicles which inhibit FSH secretory dynamics sufficiently to prevent selection of a dominant follicle.

Androgens↗
PubMed2006

Molecular evidence that growth of dominant follicles involves a reduction in follicle-stimulating hormone dependence and an increase in luteinizing hormone dependence in cattle.

The bovine dominant follicle (DF) model was used to identify molecular mechanisms potentially involved in initial growth of DF during the low FSH milieu of ovarian follicular waves. Follicular fluid and RNA from granulosa and theca cells were harvested from 10 individual DF obtained between 2 and 5.5 days after emergence of the first follicular wave of the estrous cycle. Follicular fluid was subjected to RIA to determine estradiol (E) and progesterone (P) concentrations and RNA to cDNA microarray analysis and (or) quantitative real-time PCR. Results showed that DF growth was associated with a decrease in intrafollicular E:P ratio and in mRNA for the FSH receptor, estrogen receptor 2 (ER beta), inhibin alpha, activin A receptor type I, and a proliferation (cyclin D2) and two proapoptotic factors (apoptosis regulatory protein Siva, Fas [TNFRSF6]-associated via death domain) in granulosa cells. In contrast, mRNAs for the LH receptor in granulosa cells and for two antiapoptotic factors (TGFB1-induced antiapoptotic factor 1, LAG1 longevity assurance homolog 4 [Saccharomyces cerevisiae]) and one proapoptotic factor (tumor necrosis factor [ligand] superfamily, member 8) were increased in theca cells. We conclude that the bovine DF provides a unique model to identify novel genes potentially involved in survival and apoptosis of follicular cells and, importantly, to determine the FSH-, estradiol-, and LH-target genes regulating its growth and function. Results provide new molecular evidence for the hypothesis that DF experience a reduction in FSH dependence but acquire increased LH dependence as they grow during the low FSH milieu of follicular waves.

Activin Receptors, Type I↗
PubMed1995

Paracrine regulation of the bovine ovarian prorenin-renin-angiotensin-system.

In the bovine ovary, prorenin production by theca cells is known to be regulated by LH. In the present study the aim was to evaluate whether LH-stimulated prorenin production could be further modulated by intraovarian factors in vitro. Theca cells were isolated from bovine ovaries by enzymatic dispersion, purified over Percoll gradient and cultured under serum-free conditions with LH/8Br-cAMP in the absence or presence of different steroids and growth factors and the amount of prorenin secreted into the medium was measured. None of the steroids used (androstendione, estradiol, progesterone) influenced the basal or LH-stimulated prorenin production. In contrast, cytokines and growth factors, like TNF alpha, TGF alpha, TGF beta and bFGF proved to be important regulators of prorenin synthesis. Whereas TNF alpha, TGF alpha and bFGF significantly reduced the LH- and 8Br-cAMP-induced prorenin synthesis at a site distal to cAMP formation, addition of TGF beta led to a further increase in the amount of prorenin secreted into the medium. None of the agonists had an influence on prorenin production by itself. The observed effects of cytokines and growth factors seemed to be confined to prorenin production only, since cell number, cell viability and steroidogenic response were not at all influenced by the agonists. We conclude that, although LH appears to be the primary regulator of ovarian prorenin production, several paracrine/autocrine intraovarian factors may be involved in "finely tuning" the secretion of prorenin, which is necessary for maintaining the differentiated state of the follicle.

Animals↗