Melatonin protects oogenesis from hypobaric hypoxia-induced fertility damage in mice.

Environmental hypoxia adversely affects reproductive health in humans and animals at high altitudes. Therefore, how to alleviate the follicle development disorder caused by hypoxia exposure and to improve the competence of fertility in plateau non-habituated female animals are important problems to be solved urgently. In this study, a hypobaric hypoxic chamber was used for 4 weeks to simulate hypoxic conditions in female mice, and the effects of hypoxia on follicle development, proliferation and apoptosis of granulosa cells, reactive oxygen species (ROS) levels in MII oocyte and 2-cell rate were evaluated. At the same time, the alleviating effect of melatonin on hypoxic exposure-induced oogenesis damage was evaluated by feeding appropriate amounts of melatonin daily under hypoxia for 4 weeks. The results showed that hypoxia exposure significantly increased the proportion of antral follicles in the ovary, the number of proliferation and apoptosis granulosa cells in the follicle, and the level of ROS in MII oocytes, eventually led to the decline of oocyte quality. However, these defects were alleviated when melatonin was fed under hypoxia conditions. Together, these findings suggest that hypoxia exposure impaired follicular development and reduced oocyte quality, and that melatonin supplementation alleviated the fertility reduction induced by hypoxia exposure.

Zichong granules promote differentiation of ovarian granulosa-like cells from human embryonic stem cells in vitro.

OBJECTIVE: To investigate whether Zichong granules (, ZCKL), a very effective herbal formula for treating infertility, have an impact on the differentiation of ovarian granulosa cells from human embryonic stem cells (hESCs) in vitro, and to explore the cellular mechanisms of its clinical effects. METHODS: Serum from ZCKL-medicated rats was prepared and used to treat mesoderm cells derived from hESCs for 6 d. Normal rat serum and a set of growth factors were used as negative and positive controls, respectively. RESULTS: ZCKL-medicated rat serum, but not normal rat serum, induced hESCs-derived mesoderm cells to differentiate into functional ovarian granulosa-like cells (OGLCs) in a similar manner to defined growth factors. The induced OGLCs resembled the morphology of native human granulosa cells, expressed granulosa cell-specific markers at both the mRNA and protein levels, produced high levels of estradiol and strongly responded to follicle-stimulating hormone stimulation. Furthermore, mRNA levels of follistatin, mothers against decapentaplegic homolog 8 and bone morphogenetic protein 6 were dynamically changed during the process. CONCLUSION: In the ZCKL treatment of infertility, one mechanism by which ZCKL may act is by influencing ovarian granulosa cell differentiation and development, possibly through the follistatin and BMP/SMAD signaling pathways.

Bee pollens originating from different species have unique effects on ovarian cell functions.

CONTEXT: The species-specific differences and mechanisms of action of bee pollen on reproduction have not been well studied. OBJECTIVE: We compared the effects of bee pollen extracts from different plants on ovarian cell functions. MATERIALS AND METHODS: We compared the effects of pollens from black alder, dandelion, maize, rapeseed, and willow at 0, 0.01, 0.1, 1, 10, or 100 µg/mL on cultured porcine ovarian granulosa cells. Cell viability was assessed with a Trypan blue test, the cell proliferation marker (PCNA), and an apoptosis marker (BAX) were assessed by immunocytochemistry. Insulin-like growth factor (IGF-I) release was measured by an enzyme-linked immunosorbent assay. RESULTS: Addition of any bee pollen reduced cell viability, promoted accumulation of both proliferation and apoptosis markers, and promoted IGF-I release. The ability of various pollens to suppress cell viability ranked as follows: rapeseed > dandelion > alder > maize > willow. The biological activity of bee pollens regarding their stimulatory action on ovarian cell proliferation ranked as follows: dandelion > willow > maize > alder > rapeseed. Cell apoptosis was promoted by pollens as follows: range > dandelion > alder > rapeseed > willow > maize. The ability of the pollens to stimulate IGF-I output are as follows: willow > dandelion > rapeseed > maize > alder. DISCUSSION: Bee pollen can promote ovarian cell proliferation by promoting IGF-I release, but it induces the dominance of apoptosis over proliferation and the reduction in ovarian cell viability in a species-specific manner. CONCLUSIONS: This is the first demonstration of adverse effects of bee pollen on ovarian cell viability and of its direct stimulatory influence on proliferation, apoptosis, and IGF-I release. The biological potency of bee pollen is dependent on the plant species.

Effects of Dietary Fatty Acids on Bovine Oocyte Competence and Granulosa Cells.

Here we assessed the effects of dietary essential fatty acids on the developmental competence of oocytes in cows and on the functionality of follicular granulosa cells (GC). Lactating German Holstein cows were supplemented from week 9 ante partum (ap) until week 8 post-partum (pp) in four dietary groups designed as (i) control (CTRL: coconut oil), (ii) essential fatty acid (EFA: linseed and safflower oil), (iii) conjugated linoleic acid (CLA: Lutalin®), and (iv) EFA+CLA (mixture of linseed oil, safflower oil and Lutalin®). EFA, CLA or EFA+CLA supplementation did not improve in vitro embryo production. However, higher proportions of α-linolenic acid (ALA) and cis-9, trans-11 CLA were observed in the follicular fluid suggesting the exposure of GC to relatively high levels of ALA and cis-9, trans-11 CLA. Consequently, we tested different concentrations of ALA and cis-9, trans-11 CLA in a bovine GC culture model for their effects on steroid production, marker gene expression and viability. Both fatty acids upregulated CD36 and downregulated the expression of FOXL2, while ALA significantly increased SOX 9 transcript levels. Both ALA and cis-9, trans-11 CLA reduced the CCND2 expression and cis-9, trans-11 CLA induced apoptosis. ALA and cis-9, trans-11 CLA significantly down-regulated the expression of STAR, CYP19A1, FSHR, LHCGR and decreased the 17ß-Estradiol (E2) and progesterone (P4) production. In conclusion, dietary lipids did not improve in vitro embryo production, while ALA and cis-9, trans-11 CLA affected the morphology and functionality of GC. This could suggestively lead to compromised follicle development and ovarian cyclicity in dairy cows.

Selenium Attenuates Chronic Heat Stress-Induced Apoptosis via the Inhibition of Endoplasmic Reticulum Stress in Mouse Granulosa Cells.

Heat stress induces apoptosis in various cells. Selenium, an essential micronutrient, has beneficial effects in maintaining the cellular physiological functions. However, its potential protective action against chronic heat stress (CHS)-induced apoptosis in granulosa cells and the related molecular mechanisms are not fully elucidated. In this study, we investigated the roles of selenium in CHS-induced apoptosis in mouse granulosa cells and explored its underlying mechanism. The heat treatment for 6-48 h induced apoptosis, potentiated caspase 3 activity, increased the expression levels of apoptosis-related gene BAX and ER stress markers, glucose-regulated protein 78 (GRP78), and CCAAT/enhancer binding protein homologous protein (CHOP) in mouse granulosa cells. The treatment with ER stress inhibitor 4-PBA significantly attenuated the adverse effects caused by CHS. Selenium treatment significantly attenuated the CHS- or thapsigargin (Tg, an ER stress activator)-induced apoptosis, potentiation of caspase 3 activity, and the increased protein expression levels of BAX, GRP78, and CHOP. Additionally, treatment of the cells with 5 ng/mL selenium significantly ameliorated the levels of estradiol, which were decreased in response to heat exposure. Consistently, administering selenium supplement alleviated the hyperthermia-caused reduction in the serum estradiol levels in vivo. Together, our findings indicate that selenium has protective effects on CHS-induced apoptosis via inhibition of the ER stress pathway. The current study provides new insights in understanding the role of selenium during the process of heat-induced cell apoptosis.

Grape Seed Procyanidin B2 Protects Porcine Ovarian Granulosa Cells against Oxidative Stress-Induced Apoptosis by Upregulating let-7a Expression.

Oxidative stress is a causal factor and key promoter of all kinds of reproductive disorders related to granulosa cell (GC) apoptosis that acts by dysregulating the expression of related genes. Various studies have suggested that grape seed procyanidin B2 (GSPB2) may protect GCs from oxidative injury, though the underlying mechanisms are not fully understood. Therefore, whether the beneficial effects of GSPB2 are associated with microRNAs, which have been suggested to play a critical role in GC apoptosis by regulating the expression of protein-coding genes, was investigated in this study. The results showed that GSPB2 treatment protected GCs from a H2O2-induced apoptosis, as detected by an MTT assay and TUNEL staining, and increased let-7a expression in GCs. Furthermore, let-7a overexpression markedly increased cell viability and inhibited H2O2-induced GC apoptosis. Furthermore, the overexpression of let-7a reduced the upregulation of Fas expression in H2O2-treated GCs at the mRNA and protein levels. Dual-luciferase reporter assay results indicated that let-7a directly targets the Fas 3'-UTR. Furthermore, the overexpression of let-7a enhanced the protective effects of GSPB2 against GC apoptosis induced by H2O2. These results indicate that GSPB2 inhibits H2O2-induced apoptosis of GCs, possibly through the upregulation of let-7a.

Effects of omega-3 polyunsaturated fatty acids on steroidogenesis and cellular development in PCOS rats.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, which is characterized by hyperandrogenism. Polyunsaturated fatty acids (PUFAs) are necessary for the body's metabolism, growth and development. Despite the well-known benefits of omega-3 polyunsaturated fatty acid supplementation on the modulation of PCOS ovarian function, relatively little is known about the precise regulation mechanism. The objective of this study was to determine the cellular and molecular mechanisms by which omega-3 regulates CYP51 expression and steroid biosynthesis during follicle growth in PCOS. The results indicated that the CYP51 expression was up-regulated in granulosa cells by omega-3. Moreover, the knockdown of CYP51 blocked omega-3 induced estradiol (E2) and progesterone (P4) synthesis as well as cellular viability and proliferation. These changes were accompanied by the up-regulation of the p-Akt level. Furthermore, the PI3K/Akt pathway was required for the regulation of CYP51 expression, steroidogenesis and cell development by omega-3 in PCOS granulosa cells. Our data demonstrate that omega-3 potentiates the cellular development and steroid biosynthesis via CYP51 up-regulation in PCOS, which are mediated through the activation of the PI3K/Akt pathway.

Induction of miR-15a expression by tripterygium glycosides caused premature ovarian failure by suppressing the Hippo-YAP/TAZ signaling effector Lats1.

Tripterygium glycosides (TGs) are chemotherapeutic drugs and immunosuppressant agents for the treatment of cancer and autoimmune diseases. We have previously reported that TGs induces premature ovarian failure (POF) by inducing cytotoxicity in ovarian granulosa cells (OGCs). Hence, we report that TGs suppress the expression of the Hippo-YAP/TAZ pathway in murine OGCs in vitro and in vivo. We found that the expressions of miR-181b, miR-15a, and miR-30d, were elevated significantly in the POF. Luciferase reporter assays confirmed that miR-15a targets Lats1 through a miR-15a binding site in the Lats1 3'UTR. Overexpression of miR-15a in mOGCs not only inhibited proliferation and growth of mOGCs, but also induced aging of mOGCs. Western blot and qPCR analysis indicated that miR-15a suppresses the expression of the Hippo-YAP/TAZ pathway in mOGCs. When the exogenous miR-15a was expressed on mouse OGCs, it could elevate the cytotoxicity effect of TG on mOGCs. We conclude that tripterygium glycosides promote cytotoxicity, senescence, and apoptosis in ovarian granulosa cells by inducing endogenous miR-15a expression and inhibiting the Hippo-YAP/TAZ pathway.

Green tea extract affects porcine ovarian cell apoptosis.

Green tea is a commonly used beverage and green tea extract is a common dietary herbal supplement manufactured into different over-the-counter products. The aim of this in vitro study was to examine the steroid hormone secretion (progesterone and 17-ß estradiol), proliferation and apoptosis of porcine ovarian granulosa cells after addition of green tea extract. Granulosa cells were incubated with green tea extract at five doses (0.1, 1, 10, 100 and 200 µg/ml) and the release of hormones by granulosa cells was assessed by EIA after 24 h exposure. The presence of proliferation and apoptotic markers was assessed by immunocytochemistry. Secretion of steroid hormones was not affected by green tea extract at all the doses in comparison to control. Also, markers of proliferation (PCNA and cyclin B1) were not affected by green tea extract. However, the highest dose (200 µg/ml) of green tea extract used in this study increased the accumulation of apoptotic markers caspase-3 and p53 in granulosa cells. In conclusion, our results indicate the impact of green tea extract at the highest dose used in this study on ovarian apoptosis through pathway that includes activation of caspase-3 and p53. Potential stimulation of these intracellular regulators could induce the process of apoptosis in ovarian cells.

Effect and underlying mechanism of Bu-Shen-An-Tai recipe on ovarian apoptosis in mice with controlled ovarian hyperstimulation implantation dysfunction.

The effect and underlying mechanism of Bu-Shen-An-Tai recipe on ovarian apoptosis in mice with controlled ovarian hyperstimulation (COH) implantation dysfunction were studied. The COH implantation dysfunction model in mice was established by intraperitoneal injection of 7.5 IU pregnant mare's serum gonadotrophin (PMSG), followed by 7.5 IU human chorionic gonadotrophin (HCG) 48 h later. Then the female mice were mated with male at a ratio of 2:1 in the same cage at 6:00 p.m. The female mice from normal group were injected intraperitoneally with normal saline and mated at the corresponding time. Day 1 of pregnancy was recorded by examining its vaginal smears at 8:00 a.m. of the next day. Fifty successfully pregnant mice were equally randomly divided into 5 groups: normal control pregnant group (NC), COH implantation dysfunction model group (COH), low dosage of Bu-Shen-An-Tai recipe group (LOW), middle dosage of Bu-Shen-An-Tai recipe group (MID) and high dosage of Bu-Shen-An-Tai recipe group (HIGH). Then from day 1, the mice in different groups were respectively intragastrically given corresponding treatments at 9:00 a.m. for 5 consecutive days. The concentrations of 17ß-estradiol (E2) and progesterone (P4) were determined by radioimmunoassay (RIA). The ultrastructural changes of ovarian tissues were observed by transmission electron microscope (TEM). The histopathological changes of ovarian tissues were observed by HE staining. The number of atretic follicles and pregnant corpus luteum were also recorded. TUNEL was applied to measure apoptotic cells of ovarian tissues. Western blotting was used to detect the protein expression of apoptosis- related factors like Bax, Bcl-2 and cleaved-caspase-3 in ovarian tissue of mice. The results showed that ovarian weight, the concentrations of E2 and P4, the number of atretic follicles and pregnant corpus luteum, as well as the apoptosis of granulosa cells were significantly increased in the COH group. The ultrastructures of ovarian tissues in the COH group showed that chromatin in granulosa cells was increased, agglutinated, aggregated or crescent-shaped. The focal cavitation and the typical apoptotic bodies could be seen in granulosa cells in the late stage of apoptosis. After the treatment with different doses of Bu-Shen-An-Tai recipe, the ultrastructural changes of ovarian granulosa cells apoptosis were dramatically improved and even disappeared under TEM. Visible mitochondria and mitochondrial cristae were increased and vacuoles were significantly reduced. The lipid dropltes were shown in a circluar or oval shape. The protein expression levels of Bax and cleaved-caspase-3 were decreased, and the expression of Bcl-2 protein was increased after treatment. It was concluded that Bu-Shen-An-Tai recipe can inhibit the apoptosis of ovarian granulosa cells, probably by up-regulating the protein expression of Bcl-2 and down-regulating Bax and cleaved-caspase-3, which contributes to the formation and maintenance of ovarian corpus luteum. It's helpful to promote the embryonic implantation, to reduce embryo loss and ultimately to improve the success rate of pregnancy.

Effects of melatonin on follicular atresia and granulosa cell apoptosis in the porcine.

The accumulation of reactive oxygen species is detrimental to the health of the ovarian follicle. The protective, antioxidant properties of melatonin, an endogenous component of porcine follicular fluid, on apoptosis of granulosa cells were evaluated in this study. Porcine granulosa cells from medium-sized (3-5 mm), healthy follicles were cultured in serum-free conditions with melatonin (0, 0.01, 0.1, 1.0, 10, and 100 ng/mL) with or without its receptor antagonist, luzindole, followed by evaluation of apoptotic markers in the treated cells. Results revealed that endogenous, intrafollicular melatonin concentration decreased as follicular atresia progressed, whereas the percentage of apoptotic granulosa cells increased. Spontaneous apoptosis of granulosa cells, triggered by serum deprivation in vitro, was remarkably blocked by melatonin (1.0 ng/mL melatonin, 32.7 ± 0.5%, vs. control, 47.0 ± 1.0%; P < 0.05). Treatment with 1.0 ng/mL of melatonin also significantly elevated MT2, SOD1, and GPX4 while lowering FASL, CHOP, and GRP78 mRNA abundance compared to the untreated control. The anti-apoptotic effect and some changes of apoptotic-relevant genes in granulosa cells invoked by melatonin supplementation were markedly blocked by luzindole, suggesting that melatonin could prevent the apoptosis of porcine granulosa cells during follicular atresia via its membrane receptors and its free-radical-scavenging activity. These findings provide new insights into the regulatory mechanism of melatonin in follicular atresia-related functions. Mol. Reprod. Dev. 83: 692-700, 2016 © 2016 Wiley Periodicals, Inc.

Runx3 transcription factor regulates ovarian functions and ovulation in female mice.

We previously demonstrated that the Runx3 transcription factor is expressed in the hypothalami, pituitaries, and ovaries of mice, and that Runx3 knockout (Runx3-/-) mice are anovulatory and their uteri are atrophic. Runx3 mRNA expression was detected in the granulosa cells of ovarian follicles, and in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC). In the present study, we examined the effects of Runx3 knockout on the gene expression of enzymes associated with steroidogenesis. We found decreased Cyp11a1 mRNA expression in Runx3-/- mouse ovaries compared with that in wild-type (wt) mouse ovaries at the age of 8 weeks. In situ hybridization analysis showed that the percentages of Cyp11a1 mRNA-expressing theca cells in follicles of Runx3-/- mice were decreased compared with those of wt mice. In accord with the alterations in Runx3-/- mouse ovaries, Kiss1 mRNA levels in ARC were increased, whereas mRNA levels of kisspeptin in AVPV were decreased, and gonadotropin-releasing hormone in the preoptic area and follicle-stimulating hormone ß subunit gene were increased in Runx3-/- mice. Following an ovarian transplantation experiment between Runx3-/- mice and wt mice, corpora lutea were observed when ovaries from Runx3-/- mice were transplanted into wt mice, but not when those from wt mice were transplanted into Runx3-/- mice, suggesting that Runx3 in the hypothalamo-pituitary system may drive gonadotropin release to induce ovulation in the ovary. These findings indicate that Runx3 plays a crucial role in the hypothalamo-pituitary-gonadal axis.

Comparative Analysis of Proteins with Stimulating Activity on Ovarian Estradiol Biosynthesis from Four Different Dioscorea Species in vitro Using Both Phenotypic and Target-based Approaches: Implication for Treating Menopause.

Rhizomes of Dioscorea species are traditionally used for relieving menopausal syndromes in Chinese medicine. The estrogen-stimulating bioactive principles have been demonstrated in our previous study. In this study, the estrogen-stimulating effects of proteins isolated from four Dioscorea species [D. alata L. (DA), D. zingiberensis C.H. Wright (DH), D. collettii var. hypoglauca (Palib.) S.J. Pei & C.T. Ting (DH), and D. oppositifolia L. (DO)] have been investigated and compared. Microscopic authentication of four Dioscorea species was performed by using paraffin and powder sections of the rhizomes. The potential bioactive proteins of four Dioscorea species have been rapidly isolated by using a DOI-antibody affinity column chromatography on immobilized antibodies against on estradiol-stimulating protein from DO (DOI), and their bioactivity has been rapidly confirmed and compared by phenotypic (i.e., estradiol-stimulating effect) and target-based (i.e., STAR, aromatase, estrogen receptors) screening approaches. The estrogen-stimulating activity of bioactive proteins from DO is the highest. In addition, bioactive proteins from DO upregulated the estradiol-metabolizing enzymes (aromatase and steroidogenic acute regulatory protein). Meanwhile, bioactive proteins from DA, DH and DO upregulated estrogen receptor ß (ERß). All bioactive proteins did not change the expression of estrogen receptor ß (ERα). The estrogen-stimulating bioactive proteins isolated from DO increased biosynthesis of estradiol and upregulated the protein expression of aromatase, steroidogenic acute regulatory protein, and ERß. The results scientifically support the traditional use of DO in Chinese medicine for relieving menopausal syndrome. Besides, proteins from DA and DZ could also upregulate the translational levels of ERß, and potentially reducing the risk of ovarian cancer, which also support the clinical use of them for treating female aging disorder. Graphical Abstract Comparative Analysis of DOI-like Proteins with Stimulating Activity on Ovarian Estradiol Biosynthesis from Four Different Dioscorea Species in vitro.

Effects of angiotensin II, atrial natriuretic peptide and endothelin-1 on proliferation and steroidogenic output of bovine granulosa cells cultured in a chemically defined system.

The role of local factors in the modulation of granulosa cell (GC) proliferation and differentiation is well described in the literature. The present work used a long-term bovine GC culture, in chemically defined medium without gonadotropins, to study the effects of angiotensin II (Ang II), atrial natriuretic peptide (ANP) and endothelin-1 (EDN1) on the steroidogenesis and cellular proliferation. Small follicles (3-5mm in diameter) from ovaries obtained in the slaughterhouse were selected according to their vascularization and follicular fluid color in order to isolate GC. Granulosa cells were plated at a density of 5×10(4)cells/well in supplemented alpha-MEM containing 3 levels (0, 10(-8)M and 10(-7)M) of Ang II, ANP, and EDN1 for up to 96h. Proliferation was evaluated by tritiated thymidine incorporation. The results showed that Ang II, ANP, and EDN1 modulate the steroidogenic output and proliferation index of GCs depending on the dose and time of culture. The selected vasoactive peptides increased androstenedione (A4) consumption in parallel with increased estradiol (E2). Although the peptides also promoted a significant increase in pregnenolone (P5) and progesterone (P4) production, the E2:P4 ratio was maintained at a high at most of the tested doses. Taken together, our in vitro data suggest that these vasoactive factors may have a direct effect on physiological follicular deviation, favoring dominance of the selected follicle.

1,25-Dihydroxyvitamin D3 increases testosterone-induced 17beta-estradiol secretion and reverses testosterone-reduced connexin 43 in rat granulosa cells.

BACKGROUND: Aromatase converts testosterone into 17beta-estradiol in granulosa cells, and the converted 17beta-estradiol contributes to follicular maturation. Additionally, excessive testosterone inhibits aromatase activity, which can lead to concerns regarding polycystic ovary syndrome (PCOS). Generally, 1,25-dihydroxyvitamin D3 (1,25D3) supplements help to improve the symptoms of PCOS patients who exhibit low blood levels of 1,25D3. Therefore, this study investigated the interaction effects of 1,25D3 and testosterone on estrogenesis and intercellular connections in rat granulosa cells. METHODS: Primary cultures of granulosa cells were treated with testosterone or testosterone plus 1,25D3, or pre-treated with a calcium channel blocker or calcium chelator. Cell lysates were subjected to western blot analysis to determine protein and phosphorylation levels, and 17beta-estradiol secretion was examined using a radioimmunoassay technique. Cell viability was evaluated by MTT reduction assay. Connexin 43 (Cx43) mRNA and protein expression levels were assessed by qRT-PCR, western blot, and immunocytochemistry. RESULTS: Testosterone treatment (0.1 and 1 microg/mL) increased aromatase expression and 17beta-estradiol secretion, and the addition of 1,25D3 attenuated testosterone (1 microg/mL)-induced aromatase expression but improved testosterone-induced 17beta-estradiol secretion. Furthermore, testosterone-induced aromatase phosphotyrosine levels increased at 10 min, 30 min and 1 h, whereas 1,25D3 increased the longevity of the testosterone effect to 6 h and 24 h. Within 18-24 h of treatment, 1,25D3 markedly enhanced testosterone-induced 17beta-estradiol secretion. Additionally, pre-treatment with a calcium channel blocker nifedipine or an intracellular calcium chelator BAPTA-AM reduced 1,25D3 and testosterone-induced 17beta-estradiol secretion. Groups that underwent testosterone treatment exhibited significantly increased estradiol receptor beta expression levels, which were not affected by 1,25D3. Neither testosterone nor 1,25D3 altered 1,25D3 receptor expression. Finally, at high doses of testosterone, Cx43 protein expression was decreased in granulosa cells, and this effect was reversed by co-treatment with 1,25D3. CONCLUSIONS: These data suggest that 1,25D3 potentially increases testosterone-induced 17beta-estradiol secretion by regulating aromatase phosphotyrosine levels, and calcium increase is involved in both 1,25D3 and testosterone-induced 17beta-estradiol secretion. 1,25D3 reverses the inhibitory effect of testosterone on Cx43 expression in granulosa cells.

Effect of hyaluronan on developmental competence and quality of oocytes and obtained blastocysts from in vitro maturation of bovine oocytes.

The objective of the present study was to evaluate the effect of hyaluronan (HA) during IVM on meiotic maturation, embryonic development, and the quality of oocytes, granulosa cells (GC), and obtained blastocysts. COCs were matured in vitro in control medium and medium with additional 0.035% or 0.07% of exogenous HA. The meiotic maturity did not differ between the analysed groups. The best rate and the highest quality of obtained blastocysts were observed when 0.07% HA was used. A highly significant difference (P < 0.001) was noted in the mean number of apoptotic nuclei per blastocyst and in the DCI between the 0.07% HA and the control blastocysts (P < 0.01). Our results suggest that addition of 0.035% HA and 0.07% HA to oocyte maturation media does not affect oocyte nuclear maturation and DNA fragmentation. However, the addition of 0.07% HA during IVM decreases the level of blastocysts DNA fragmentation. Finally, our results suggest that it may be risky to increase the HA concentration during IVM above 0.07% as we found significantly higher Bax mRNA expression levels in GC cultured with 0.07% HA. The final concentration of HA being supplemented to oocyte maturation media is critical for the success of the IVP procedure.

[Effect of Yangjing Zhongyu Decoction on mRNA and protein expression of PCNA, StAR, and FSHR in ovarian granulosa cells cultured by excess androgen].

OBJECTIVE: To observe the effect of Yangjing Zhongyu Decoction (YZD) on mRNA and protein expression of PCNA, StAR, and FSHR in ovarian granulose cells (GCs) cultured by excess androgen. METHODS: Ovarian GCs from porcine follicles were isolated and cultured in vitro. Follicular stimulating hormone (FSH) or YZD was added in the GCs treated by excess testosterone propionate. Totally 48 h later mRNA and protein expression of PCNA, StAR, and FSHR were detected by RT-PCR and Western blot. RESULTS: Excess androgen inhibited mRNA and protein expression of PCNA, StAR, and FSHR of GCs. FSH and YZD could antagonize inhibition of excess androgens, and promote mRNA and protein expression of PCNA, StAR, and FSHR in GCs. CONCLUSION: YZD could antagonize the inhibition of excess androgen on mRNA and protein expression of PCNA, StAR and FSHR in GCs. Thus, we inferred that YZD could improve the follicle dysplasia by promoting mRNA and protein expression of PCNA, StAR and FSHR in GCs.

[Effect of Bushen Tiaojing Recipe containing serum on FSH/cAMP-PKA pathway in in vitro cultured human ovarian granular cells].

OBJECTIVE: To explore the potential molecular mechanisms for Bushen Tiaojing Recipe (BTR) improving the endocrine function of ovarian granular cells by observing the effect of BTR containing serum on follicle stimulating hormone/cyclic adenosine monophosphate-protein kinase A (FSH/ cAMP-PKA) pathway in in vitro cultured human ovarian granular cells. METHODS: The primary ovarian granular cells collected from in vitro fertilization-embryo transfer patients were cultured for 24 h. The human and rat serum containing different concentrations of BTR (low, medium, high dose), and their normal serums were co-incubated with ovarian granular cells for 48 h respectively, and then they were divided into the low, medium, high dose BTR groups and the control group. The levels of estradiol (E2), progesterone (P), and cyclic adenosine monophosphate (cAMP) in the culture medium were measured by radioimmunoassay. The protein expression of FSHR in ovarian granular cells was detected by Western Blot. The mRNA expression of follicle stimulating hormone receptor (FSHR) and P450 aromatase (P450arom) in ovarian granular cells were detected by Real-time PCR. RESULTS: In human BTR containing serum groups: Compared with control group, the levels of E2 and cAMP in the culture medium were higher (both P < 0.05) in the medium and high dose BTR groups; the levels of P in the culture medium decreased in the medium dose BTR group (P < 0.01). The protein and mRNA expression of FSHR in ovarian granular cells increased (all P < 0.01), the mRNA expressions of P450arom in ovarian granular cells were higher (P < 0.05, P< 0.01) in the medium and high dose BTR groups. In rat BTR containing serum groups: Compared with the control group, the levels of E2 in the culture medium were higher (all P < 0.01), cAMP in the culture medium were higher (P < 0.05, P < 0.01) in the medium and high dose BTR group; the levels of P in the culture medium decreased in the medium dose BTR group (P < 0.01). The protein and mRNA expression of FSHR in ovarian granular cells were higher (all P < 0.01), the mRNA expression of P450arom in ovarian granular cells increased in the medium and high dose BTR groups (P < 0.05, P < 0.01). CONCLUSION: BTR could possibly improve the endocrine function of ovarian granular cells by regulating main effector molecules FSHR, cAMP, P450arom, and E2 in FSH/cAMP-PKA pathway of ovarian granular cells.

Notch signaling regulates ovarian follicle formation and coordinates follicular growth.

Ovarian follicles form through a process in which somatic pregranulosa cells encapsulate individual germ cells from germ cell syncytia. Complementary expression of the Notch ligand, Jagged1, in germ cells and the Notch receptor, Notch2, in pregranulosa cells suggests a role for Notch signaling in mediating cellular interactions during follicle assembly. Using a Notch reporter mouse, we demonstrate that Notch signaling is active within somatic cells of the embryonic ovary, and these cells undergo dramatic reorganization during follicle histogenesis. This coincides with a significant increase in the expression of the ligands, Jagged1 and Jagged2; the receptor, Notch2; and the target genes, Hes1 and Hey2. Histological examination of ovaries from mice with conditional deletion of Jagged1 within germ cells (J1 knockout [J1KO]) or Notch2 within granulosa cells (N2 knockout [N2KO]) reveals changes in follicle dynamics, including perturbations in the primordial follicle pool and antral follicle development. J1KO and N2KO ovaries also contain multi-oocytic follicles, which represent a failure to resolve germ cell syncytia, and follicles with enlarged oocytes but lacking somatic cell growth, signifying a potential role of Notch signaling in follicle activation and the coordination of follicle development. We also observed decreased cell proliferation and increased apoptosis in the somatic cells of both conditional knockout lines. As a consequence of these defects, J1KO female mice are subfertile; however, N2KO female mice remain fertile. This study demonstrates important functions for Jagged1 and Notch2 in the resolution of germ cell syncytia and the coordination of somatic and germ cell growth within follicles of the mouse ovary.

Increasing cell plating density mimics an early post-LH stage in cultured bovine granulosa cells.

Cultured ovarian granulosa cells are essential models to study molecular mechanisms of gene regulation during folliculogenesis. Here, we characterize primary tissue culture models for bovine granulosa cells by morphological and physiological parameters and by novel molecular luteinization markers, as transcript abundance and DNA methylation levels. The data show that: (1) collagen substrate increased the number of attached, viable cells; (2) the expression of the key transcripts of estrogen synthesis, CYP19A1, could be induced and maintained in granulosa cells from small to medium but not from large follicles, whereas (3) only granulosa cells from large but not from smaller follicles were responsive to LH; (4) serum supplementation unfavorably transformed the cellular phenotype, induced proliferation and PCNA expression, reduced or abolished the transcript abundance of steroidogenic key genes and of gonadotropin receptor genes, CYP11A1, CYP19A1, FSHR and LHCGR but, however, did not increase the abundance of the luteinization-specific marker transcripts PTGS2, PTX3, RGS2 and VNN2; but (5) by increasing the plating density, estradiol production and the abundance of CYP19A1 transcripts, in particular those derived from the main ovarian promoter P2, were decreased concurrently leaving P2-specific DNA methylation levels unchanged, whereas progesterone secretion was stimulated and the expression of both luteinization-specific marker transcripts, RGS2 and VNN2, was significantly induced. From these data, we conclude that increasing the plating density induces a different, partly complementary, physiological and gene expression profile in cultured bovine granulosa cells and drives the cells towards an early post-LH stage of luteinization, even in the absence of luteinizing agents.