435. Follicle differentiation and luteinisation in the mouse is associated with hypoxia inducible factor activity

2008 ◽  
Vol 20 (9) ◽  
pp. 115
Author(s):  
K. Tam ◽  
D. Russell ◽  
K. Kind ◽  
J. Thompson
Keyword(s):  
Granulosa Cells ◽  
Target Genes ◽  
Ovarian Function ◽  
Egfp Expression ◽  
Corpora Lutea ◽  
Limited Information ◽  
Antral Follicles ◽  
Follicle Differentiation

Hypoxia inducible factors (HIF) are transcription factors that mediate the response to hypoxic stress. Under hypoxic conditions, HIF is stabilised, translocates to the nucleus, and binds to the Hypoxia Response Elements (HRE) upstream of numerous target genes involved in angiogenesis and glycolysis, including Vegf, Glut-1 and Ldha. Little is known about the role of HIFs in regulating ovarian function. In rat granulosa cells, FSH stimulates HIF 1α via the PI3K/Akt pathway, demonstrating a role for HIFs during follicular development. In contrast, there is limited information regarding the role of HIFs during corpus luteum formation. In this study we investigated whether HIFs play a role in follicle differentiation and luteinisation. Prepubertal C57Bl6 females were stimulated with eCG (5 IU) followed 46 h later by hCG (5 IU). Mice were sacrificed at 0, 4, 8, 12, 16 and 24 h post hCG and granulosa cells were collected for Western analysis of HIF-1a protein. To investigate HIF activation in the ovary, a transgenic reporter mouse line was developed by lenti-viral incorporation of an HRE (4)-SV40-eGFP construct. Ovaries were collected from mice plugged day 1, 4 and 8 for CL analysis in vivo.A time- dependent increase of HIF 1α protein levels in granulosa cells, maximal around time of ovulation, was observed. Ovaries from cycling HRE-eGFP transgenic mice exhibited no eGFP in primordial, primary or preantral follicles. Upon antrum formation, eGFP was evident in occasional sections in antral follicles but HIF signalling was restricted within the theca. In contrast, corpora lutea on pregnancy day 1, 4 and 8 readily expressed eGFP and eGFP expression increases as luteinisation progresses.These results demonstrate that in vivo HIFs may play a role in folliculogenesis, but this is restricted to theca cells of antral follicles before hCG stimulation. Following hCG, maximal HIF activity is associated with the time of ovulation. In addition, HIF activity is maintained during luteinisation.

scholarly journals 279.Infertility in mice with null mutation of the Egr-1 transcription factor

2004 ◽  
Vol 16 (9) ◽  
pp. 279 ◽  
Author(s):  
D. L. Russell
Keyword(s):  
Transcription Factor ◽  
Target Genes ◽  
Ovarian Function ◽  
Ovarian Follicle ◽  
Follicular Development ◽  
Prostaglandin E ◽  
Lh Receptor ◽  
Expression Of Genes

Female infertility has been reported in two lines of mice with mutation of the Egr-1 gene. One underlying cause of this defect is deficient LH production by pituitary gonadotropes. However, Egr-1 is also acutely regulated by both FSH and LH in ovarian granulosa cells (1). A role for this transcription factor in regulating gonadotrophin responsive target genes and ovarian function is hypothesised. Indeed the LH-receptor is a proposed target of Egr-1 regulation, but this has not been investigated in detail in vivo and is difficult to reconcile with the pattern of Egr-1 expression. In this study, the role of Egr-1 within the ovarian follicle was investigated using exogenous gonadotropin replacement in Egr-1–/– mice . Adult Egr-1–/– female mice superovulated by sequential PMSG and hCG stimulation and mated with proven male breeders failed to produced offspring while 90% of heterozygous females got pregnant and produced litters (7.4 � 2.9 pups per litter) within 22 days of stimulation. Recovery of oocytes from oviducts of immature superovulated mice revealed a reduced ovulation rate in null females (6.3 � 3.8 oocytes) compared to their heterozygous (18.0 � 6.5) and WT (17.8 � 6.8) littermates. Gross morphology and histology of exogenously stimulated ovaries were indistinguishable from their heterozygous or WT counterparts. Surprisingly, no alteration was detectable in the mRNA expression of previously reported direct Egr-1 responsive genes, namely LH-receptor and membrane prostaglandin E synthase (mPGES). Nor were mRNA for two critical ovulatory genes with putative Egr-1 response elements, ADAMTS-1 or versican V1 altered. Temporal and spatial expression of genes involved in ovarian steroidogenesis, P450scc and Cyp17 and LH-receptor, were indistinguishable from normal littermates during exogenously controled follicular development. Combined observations of acute Egr-1 induction by gonadotropins, reduced ovulation and complete infertility suggest an important role for Egr-1 in ovarian function. However, genes identified as targets of Egr-1 regulation in other studies proved to be Egr-1 independent in this model. (1) Russell et al. (2003) Mol. Endo. 17, 520.

Epidermal growth factor acts directly on the sheep ovary in vivo to inhibit oestradiol-17β and inhibin secretion and enhance progesterone secretion

1993 ◽  
Vol 137 (2) ◽  
pp. 253-264 ◽  
Author(s):  
J. F. Murray ◽  
J. A. Downing ◽  
G. Evans ◽  
J. K. Findlay ◽  
R. J. Scaramuzzi
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Granulosa Cells ◽  
Ovarian Function ◽  
Jugular Vein ◽  
Follicular Phase ◽  
Antral Follicles ◽  
Progesterone Secretion ◽  
Epidermal Growth

ABSTRACT Epidermal growth factor (EGF) is a potential intra-ovarian modulator of gonadotroph action on differentiated follicular cells. Specific binding sites have been identified in the ovary and functional differentiation in cultured granulosa cells can be modulated by treatment with EGF. The aim of this study was to determine if EGF was capable of altering ovarian function in vivo during the follicular phase of the sheep oestrous cycle. Fourteen cross-bred ewes with ovarian autotransplants were treated with progestagen pessaries for 12 days. Three ewes were infused with murine EGF (mEGF) via the jugular vein (75 μg/kg bodyweight per 12 h) during the 12 h preceding progestagen pessary withdrawal, and received an injection of a prostaglandin analogue at 0 h to induce luteolysis. Over the same time-period, two doses of EGF were administered to other groups of ewes by infusion into the ovarian artery (low: 6 μg/12 h, n = 3 and high: 60 μg/12 h, n = 3). The remaining five ewes were not infused with EGF (controls). Jugular and ovarian venous blood samples were taken at 10-min intervals at two stages during the follicular phase (21–27 h and 38–42 h after pessary withdrawal) and every 2 h from 44 to 76 or 86 h. mEGF, LH, FSH, inhibin, androstenedione, oestradiol-17β and progesterone concentrations in plasma were determined using radioimmunoassays. The secretion rates of androstenedione, oestradiol, progesterone and inhibin by the ovary were calculated. EGF acted directly on the ovary in a dose-dependent manner. Oestradiol secretion was inhibited following treatment with EGF but androstenedione secretion was unaffected. EGF appears therefore to act within the granulosa cells to inhibit aromatization. Inhibin secretion was also suppressed by treatment with EGF, though it was not possible to determine if this was caused by a direct or indirect action of EGF on granulosa cells. The rate of progesterone secretion increased in ewes receiving systemic (i.e. via the jugular vein) and high-dose intra-arterial infusions of EGF, even though a preovulatory LH surge was not observed in these animals during the entire experimental period. Concomitant increases in both LH and FSH secretion were associated with these effects of EGF on ovarian function. In conclusion, EGF appears to act directly on the granulosa cells of the follicle to inhibit aromatization and also to inhibit inhibin production. The low levels of oestradiol and inhibin in the presence of high levels of gonadotrophin indicate that atresia may have been induced in medium to large antral follicles. The increase in progesterone secretion following high doses of EGF may be derived from a luteinized follicle. FSH-stimulated functions cease when a follicle luteinizes and progesterone secretion commences. EGF treatment inhibited both oestradiol and inhibin secretion whilst enhancing progesterone which suggests that EGF may also be involved in the induction of functional luteinization. EGF or an EGF-like substance may therefore be an important factor in the induction of functional luteinization, with atresia occurring in antral follicles which are exposed to EGF too early in their development. Journal of Endocrinology (1993) 137, 253–264

scholarly journals Inhibition of matrix metalloproteinases in Siberian hamsters impedes photostimulated recrudescence of ovaries

Reproduction ◽  
2010 ◽  
Vol 140 (6) ◽  
pp. 875-883 ◽  
Author(s):  
Julie Whited ◽  
Asha Shahed ◽  
Carling F McMichael ◽  
Kelly A Young
Keyword(s):  
Matrix Metalloproteinases ◽  
Ovarian Function ◽  
Corpora Lutea ◽  
Gelatinase Activity ◽  
Antral Follicles ◽  
Mmp Inhibitor ◽  
Siberian Hamsters ◽  
First Time ◽  
Long Photoperiod

Exposure of Siberian hamsters to short photoperiod for 14 weeks induces ovarian regression. Subsequent transfer to long photoperiod restores ovarian function, and 2 weeks of photostimulation increases plasma estradiol (E2), antral follicles, and corpora lutea (CL). Because tissue remodeling involved with photostimulated ovarian recrudescence is associated with differential expression of matrix metalloproteinases (MMPs), we hypothesized that inhibiting MMP activity using a broad-spectrumin vivoMMP inhibitor, GM6001, would curtail recrudescence. One group of hamsters was placed in long days (LD; 16 h light:8 h darkness) for 16 weeks. Another group was placed in inhibitory short days (SD; 8 h light:16 h darkness) for 14 weeks. A third group was placed in SD for 14 weeks and transferred to LD for 2 weeks to stimulate recrudescence. During weeks 14–16, animals were either not treated or treated daily with i.p. injections of GM6001 (20 mg/kg) or vehicle (DMSO). GM6001 reduced gelatinase activity and decreased immunohistochemical staining for MMP1, MMP2, and MMP3 compared with vehicle. No differences between controls, vehicle, or GM6001 treatment were observed among LD animals, despite a trend toward reduction in CL and E2with GM6001. Although SD reduced ovarian function, photostimulation of transferred controls increased uterine mass, plasma E2, appearance of antral follicles, and CL. With GM6001 treatment, photostimulation failed to increase uterine mass, plasma E2, antral follicles, or CL. These data show, for the first time, thatin vivoGM6001 administration inhibits MMP activity in hamster ovaries during photostimulation, and indicate that this inhibition may impede photostimulated recrudescence of ovaries. This study suggests an intriguing link between MMP activity and return to ovarian function during photostimulated recrudescence.

scholarly journals NUSAP1 Promotes Gastric Cancer Progression Through Regulation of Yap Stability

2020 ◽  
Author(s):  
Hui Guo ◽  
Jianping Zou ◽  
Ling Zhou ◽  
Yan He ◽  
Miao Feng ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Target Genes ◽  
Hippo Pathway ◽  
Critical Role ◽  
Xenograft Model ◽  
Migration And Invasion

Abstract Background:Nucleolar and spindle associated protein (NUSAP1) is involved in tumor initiation, progression and metastasis. However, there are limited studies regarding the role of NUSAP1 in gastric cancer (GC). Methods: The expression profile and clinical significance of NUSAP1 in GC were analysed in online database using GEPIA, Oncomine and KM plotter, which was further confirmed in clinical specimens.The functional role of NUSAP1 were detected utilizing in vitro and in vivo assays. Western blotting, qRT-PCR, the cycloheximide-chase, immunofluorescence staining and Co-immunoprecipitaion (Co-IP) assays were performed to explore the possible molecular mechanism by which NUSAP1 stabilizes YAP protein. Results:In this study, we found that the expression of NUSAP1 was upregulated in GC tissues and correlates closely with progression and prognosis. Additionally, abnormal NUSAP1 expression promoted malignant behaviors of GC cells in vitro and in a xenograft model. Mechanistically, we discovered that NUSAP1 physically interacts with YAP and furthermore stabilizes YAP protein expression, which induces the transcription of Hippo pathway downstream target genes. Furthermore, the effects of NUSAP1 on GC cell growth, migration and invasion were mainly mediated by YAP. Conclusions:Our data demonstrates that the novel NUSAP1-YAP axis exerts an critical role in GC tumorigenesis and progression, and therefore could provide a novel therapeutic target for GC treatment.

Seasonal differences in ovarian activity in cows

1984 ◽  
Vol 102 (2) ◽  
pp. 189-198 ◽  
Author(s):  
K. P. McNatty ◽  
N. Hudson ◽  
M. Gibb ◽  
K. M. Henderson ◽  
S. Lun ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Ovarian Function ◽  
Plasma Concentrations ◽  
Peak Frequency ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Aromatase Activity ◽  
Plasma Prolactin ◽  
Seasonal Differences ◽  
Time Of Year

ABSTRACT The plasma concentrations of LH and prolactin and various parameters of ovarian function were examined in cows on known days of the oestrous cycle during May and June (autumn and winter) and during October (spring). Luteinizing hormone peak frequency and plasma prolactin concentrations were significantly higher in October than during the May–June period (LH, P<0·05; prolactin, P<0·01). The mean diameters of large healthy follicles (≥8 mm diameter) and the dominant oestrogen-secreting follicles were significantly larger (P<0·01 for both follicle types) and each follicle contained more granulosa cells (both P<0·01) in May–June than in October. The LH responsiveness of theca interna with respect to androstenedione production and the levels of aromatase activity in granulosa cells did not differ with time of year. The corpora lutea were heavier (P<0·05) and secreted more progesterone (P<0·01) in May–June than in October. It is concluded that seasonal differences in ovarian activity exist in cows and that these differences are probably the consequence of seasonal differences in gonadotrophin secretion. J. Endocr. (1984) 102, 189–198

scholarly journals Oocyte-Specific Overexpression of Mouse Bone Morphogenetic Protein-15 Leads to Accelerated Folliculogenesis and an Early Onset of Acyclicity in Transgenic Mice

Endocrinology ◽  
2008 ◽  
Vol 149 (6) ◽  
pp. 2807-2815 ◽  
Author(s):  
Heather E. McMahon ◽  
Osamu Hashimoto ◽  
Pamela L. Mellon ◽  
Shunichi Shimasaki
Keyword(s):  
Transgenic Mice ◽  
Bone Morphogenetic Protein ◽  
Early Onset ◽  
Ovarian Function ◽  
Chimeric Protein ◽  
Mature Protein ◽  
Follicle Growth ◽  
Morphogenetic Protein

Whereas mutations in the bmp15 gene cause infertility in ewes and women due to defects in folliculogenesis, most defects in female mice lacking bone morphogenetic protein (BMP)-15 are confined to the ovulation process, supportive of the observation that functional mouse BMP-15 is barely detected in oocytes in vivo until after the LH surge. In addition, the mouse BMP-15 proprotein is not processed into the functional mature protein in transfected cells. However, a chimeric protein consisting of the human proregion, human cleavage site, and mouse mature region (termed hhmBMP-15) is processed and the mature protein secreted. To study the role of BMP-15 in folliculogenesis, we generated transgenic mice overexpressing hhmBMP-15, exclusively in oocytes during folliculogenesis and confirmed the overexpression of mouse BMP-15 mature protein. Immature transgenic mice exhibited accelerated follicle growth with decreased primary follicles and an increase in secondary follicles. Granulosa cells of immature mice displayed an increased mitotic index and decreased FSH receptor mRNA expression. Adult mice had normal litter sizes but an increased number of atretic antral follicles. Interestingly, aging mice exhibited an early onset of acyclicity marked by increased diestrus length and early occurrence of constant diestrus. These findings indicate the role of BMP-15 in vivo in promoting follicle growth and preventing follicle maturation, resulting in an early decline in the ovarian reserve of transgenic mice. Therefore, the lack of mouse BMP-15 during early folliculogenesis in the wild-type mice may be relevant to their polyovulatory nature as well as the preservation of ovarian function as the mice age.

scholarly journals Histone H3K23-specific acetylation by MORF is coupled to H3K14 acylation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Suk Min Jang ◽  
Catherine Lachance ◽  
Wenyi Mi ◽  
Jie Lyu ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Memory Impairment ◽  
Target Genes ◽  
Epigenetic Mark ◽  
Mechanistic Insight ◽  
Genomic Analyses ◽  
Insight Into

Abstract Acetylation of histone H3K23 has emerged as an essential posttranslational modification associated with cancer and learning and memory impairment, yet our understanding of this epigenetic mark remains insufficient. Here, we identify the native MORF complex as a histone H3K23-specific acetyltransferase and elucidate its mechanism of action. The acetyltransferase function of the catalytic MORF subunit is positively regulated by the DPF domain of MORF (MORFDPF). The crystal structure of MORFDPF in complex with crotonylated H3K14 peptide provides mechanistic insight into selectivity of this epigenetic reader and its ability to recognize both histone and DNA. ChIP data reveal the role of MORFDPF in MORF-dependent H3K23 acetylation of target genes. Mass spectrometry, biochemical and genomic analyses show co-existence of the H3K23ac and H3K14ac modifications in vitro and co-occupancy of the MORF complex, H3K23ac, and H3K14ac at specific loci in vivo. Our findings suggest a model in which interaction of MORFDPF with acylated H3K14 promotes acetylation of H3K23 by the native MORF complex to activate transcription.

scholarly journals Inhibition of oocyte growth factors in vivo modulates ovarian folliculogenesis in neonatal and immature mice

Reproduction ◽  
2010 ◽  
Vol 139 (3) ◽  
pp. 587-598 ◽  
Author(s):  
Samu Myllymaa ◽  
Arja Pasternack ◽  
David G Mottershead ◽  
Matti Poutanen ◽  
Minna M Pulkki ◽  
...  
Keyword(s):  
Growth Factors ◽  
Granulosa Cells ◽  
Microscopic Analysis ◽  
Corpora Lutea ◽  
Electron Microscopic ◽  
Oocyte Growth ◽  
Long Term Study ◽  
Ovarian Folliculogenesis

Growth differentiation factor-9 (GDF9) and bone morphogenetic protein-15 (BMP15) are among the key regulators transmitting the signaling between the oocyte and the surrounding granulosa cells. Previously, it has been shown that a recombinant BMP type II receptor ectodomain–Fc fusion protein (BMPR2ecd–Fc) is able to inhibit the actions of GDF9 and BMP15 in vitro. Here, we have produced bioactive BMPR2ecd–Fc, which was injected i.p. into neonatal mice. Early folliculogenesis was first studied by injecting mice five times with various doses of BMPR2ecd–Fc during the postnatal days 4–12. Folliculogenesis was affected dose dependently, as evidenced by a decreased mitogenesis of granulosa cells of the growing follicles. Furthermore, we also noticed a decrease in the number of secondary and tertiary follicles as well as an increase in the oocyte size. Electron microscopic analysis revealed that the ultrastructure of the granulosa cells of the primary follicles was not affected by the BMPR2ecd–Fc treatment. A second study was conducted to investigate whether a longer treatment with 12 injections during postnatal days 4–28 would inhibit folliculogenesis. Similar effects were observed in the two studies on the early follicular developmental stages. However, in the long-term study, later stages of folliculogenesis were not blocked but rather increased numbers of antral follicles, preovulatory follicles, and corpora lutea were found. We conclude that BMPR2ecd–Fc is a potent modulator of ovarian folliculogenesis in vivo, and thus, is a valuable tool for studying the physiology and downstream effects of oocyte-derived growth factors in vivo.

scholarly journals Laminin-alpha6beta1 integrin interaction enhances survival and proliferation and modulates steroidogenesis of ovine granulosa cells

2002 ◽  
Vol 172 (1) ◽  
pp. 45-59 ◽  
Author(s):  
F Le Bellego ◽  
C Pisselet ◽  
C Huet ◽  
P Monget ◽  
D Monniaux
Keyword(s):  
Estrous Cycle ◽  
Granulosa Cells ◽  
Physiological Role ◽  
Follicular Development ◽  
Antral Follicles ◽  
Final Development ◽  
Beta 1 Integrin ◽  
Arginine Glycine Aspartic Acid

This study aimed to determine the physiological role of laminin (LN) and its receptor, alpha(6)beta(1) integrin, in controlling the functions of granulosa cells (GC) during follicular development in sheep ovary. Immunohistochemistry experiments showed the presence of increasing levels of LN (P<0.0001), and high levels of mature alpha(6)beta(1) integrin in GC layers of healthy antral follicles during the follicular and the preovulatory phases of the estrous cycle. In vitro, the addition of a function-blocking antibody raised against alpha(6) subunit (anti-alpha(6) IgG) to the medium of ovine GC cultured on LN impaired cell spreading (P<0.0001), decreased the proliferation rate (P<0.05) and increased the apoptosis rate (P<0.05). Furthermore, addition of anti-alpha(6) IgG enhanced estradiol (E2) secretion by GC in the presence or absence of follicle-stimulating hormone (FSH), luteinizing hormone or insulin-like growth factor-I in culture medium (P<0.0001), and inhibited progesterone (P4) secretion in basal conditions or in the presence of low (0.5 ng/ml) FSH concentrations only (P<0.0001). The anti-alpha(6) IgG effect was specific to an interaction of LN with alpha(6)beta(1) integrin since it was ineffective on GC cultured on heat-denatured LN, RGD (arginine-glycine-aspartic acid) peptides and non-coated substratum. Hence, this study established that alpha(6)beta(1) integrin 1) was expressed in GC of antral follicles, 2) mediated the actions of LN on survival, proliferation and steroidogenesis of GC, and 3) was able to dramatically modulate P4 and E2 secretion by GC in vitro. It is suggested that during the follicular and the preovulatory phases of the estrous cycle, the increasing levels of LN in GC of large antral follicles might support their final development to ovulation.

scholarly journals Transgenic Analysis Reveals that Thyroid Hormone Receptor Is Sufficient To Mediate the Thyroid Hormone Signal in Frog Metamorphosis

2004 ◽  
Vol 24 (20) ◽  
pp. 9026-9037 ◽  
Author(s):  
Daniel R. Buchholz ◽  
Akihiro Tomita ◽  
Liezhen Fu ◽  
Bindu D. Paul ◽  
Yun-Bo Shi
Keyword(s):  
Thyroid Hormone ◽  
Hormone Receptor ◽  
Target Genes ◽  
Thyroid Hormone Receptor ◽  
Gene Activation ◽  
Inducible Promoter ◽  
Vertebrate Development ◽  
Transcription System

ABSTRACT Thyroid hormone (T3) has long been known to be important for vertebrate development and adult organ function. Whereas thyroid hormone receptor (TR) knockout and transgenic studies of mice have implicated TR involvement in mammalian development, the underlying molecular bases for the resulting phenotypes remain to be determined in vivo, especially considering that T3 is known to have both genomic, i.e., through TRs, and nongenomic effects on cells. Amphibian metamorphosis is an excellent model for studying the role of TR in vertebrate development because of its total dependence on T3. Here we investigated the role of TR in metamorphosis by developing a dominant positive mutant thyroid hormone receptor (dpTR). In the frog oocyte transcription system, dpTR bound a T3-responsive promoter and activated the promoter independently of T3. Transgenic expression of dpTR under the control of a heat shock-inducible promoter in premetamorphic tadpoles led to precocious metamorphic transformations. Molecular analyses showed that dpTR induced metamorphosis by specifically binding to known T3 target genes, leading to increased local histone acetylation and gene activation, similar to T3-bound TR during natural metamorphosis. Our experiments indicated that the metamorphic role of T3 is through genomic action of the hormone, at least on the developmental parameters tested. They further provide the first example where TR is shown to mediate directly and sufficiently these developmental effects of T3 in individual organs by regulating target gene expression in these organs.

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