020. Oocyte signalling molecules and their effects on reproduction in ruminants

2005 ◽  
Vol 17 (9) ◽  
pp. 66
Author(s):  
K. P. McNatty
Keyword(s):  
Granulosa Cells ◽  
Point Mutations ◽  
Follicular Development ◽  
Ovis Aries ◽  
Ovulation Rate ◽  
Active Immunisation ◽  
Primary Stage ◽  
Signalling Molecules ◽  
Stage Of Development

Sheep (Ovis aries) are a highly diverse species with more than 900 different breeds that vary significantly in their physiological characteristics including ovulation rate and fecundity. From examination of inherited patterns of ovulation rate in sheep, several breeds have been identified with point mutations in two growth factor genes that are expressed in oocytes. Currently, five different point mutations have been identified in the BMP15 (GDF9b) gene and one in GDF9. Animals heterozygous for the GDF9 and/or the BMP15 mutations have higher ovulation rates (i.e. +0.6 to +5.0) than their wild-type contemporaries. In contrast, those homozygous for any of the aforementioned BMP15 or GDF9 mutations are sterile due to abnormal follicular development from the primary stage of growth. In bovine and ovine ovaries, GDF9 is expressed exclusively in oocytes throughout follicular growth from the primordial stage of development, whereas in sheep BMP15 is expressed exclusively in oocytes from the primary stage: no data for BMP15 are available for the cow. In vitro, ovine GDF9 (oGDF9) has no effect on 3H-thymidine incorporation by either bovine or ovine granulosa cells, whereas oBMP15 has modest (1.2 to 1.6-fold; P < 0.05) stimulatory effects. GDF9 or BMP15 alone inhibited progesterone production by bovine granulosa cells, whereas with ovine cells only GDF9 was inhibitory. The effects of GDF9 and BMP15 together were often cooperative and not always the same as those observed for each factor alone. Active immunisation of ewes with BMP15 and/or GDF9 peptides affected ovarian follicular development and ovulation rate. Depending on the GDF9 and/or BMP15 vaccine formulation, ovulation rate was either increased or suppressed. For example, immunisation of ewes with a BMP15 peptide in a water based adjuvant has led to a 25% increase in lambs born per ewe lambing. Collectively the evidence suggests that oocyte signalling molecules have profound effects on reproduction in mammals including rodents, humans and ruminants. Moreover, that in vivo manipulation of these oocyte signalling molecules provides a new approach to managing the fertility of ruminants.

Meat and Livestock Association Plenary Lecture 2005. Oocyte signalling molecules and their effects on reproduction in ruminants

2006 ◽  
Vol 18 (4) ◽  
pp. 403 ◽  
Author(s):  
Kenneth P. McNatty ◽  
Stephen Lawrence ◽  
Nigel P. Groome ◽  
Mohammed F. Meerasahib ◽  
Norma L. Hudson ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Point Mutations ◽  
Follicular Development ◽  
Ovis Aries ◽  
Ovulation Rate ◽  
Active Immunisation ◽  
Signalling Molecules ◽  
Stage Of Development

Sheep (Ovis aries) are a highly diverse species, with more than 900 different breeds that vary significantly in their physiological characteristics, including ovulation rate and fecundity. From examination of inherited patterns of ovulation rate, several breeds have been identified with point mutations in two growth factor genes that are expressed in oocytes. Currently, five different point mutations have been identified in the BMP15 (GDF9b) gene and one in GDF9. Animals heterozygous for the GDF9 and/or the BMP15 mutations have higher ovulation rates than their wild-type counterparts. In contrast, those homozygous for any of the aforementioned BMP15 or GDF9 mutations are sterile owing to arrested follicular development. In bovine and ovine ovaries, GDF9 was expressed exclusively in oocytes throughout follicular growth from the primordial stage of development, whereas in sheep BMP15 was expressed exclusively in oocytes from the primary stage: no data for the ontogeny of BMP15 expression are currently available for cattle. In vitro, ovine growth differentiation factor 9 (oGDF9) has no effect on 3H-thymidine incorporation by either bovine or ovine granulosa cells, whereas ovine bone morphogenetic protein 15 (oBMP15) has modest (1.2- to 1.6-fold; P < 0.05) stimulatory effects. Ovine GDF9 or oBMP15 alone inhibited progesterone production by bovine granulosa cells, whereas in ovine cells only oGDF9 was inhibitory. The effects of oGDF9 and oBMP15 together were often cooperative and not always the same as those observed for each factor alone. Active immunisation of ewes with BMP15 and/or GDF9 peptides affected ovarian follicular development and ovulation rate. Depending on the GDF9 and/or BMP15 vaccine formulation, ovulation rate was either increased or suppressed. A primary and single booster immunisation of ewes with a BMP15 peptide in a water-based adjuvant has led to 19–40% increases in lambs born per ewe lambing. Collectively, the evidence suggests that oocyte signalling molecules have profound effects on reproduction in mammals, including rodents, humans and ruminants. Moreover, in vivo manipulation of these oocyte signalling molecules provides new opportunities for the management of the fertility of ruminants.

scholarly journals The oocyte and its role in regulating ovulation rate: a new paradigm in reproductive biology

Reproduction ◽  
2004 ◽  
Vol 128 (4) ◽  
pp. 379-386 ◽  
Author(s):  
K P McNatty ◽  
L G Moore ◽  
N L Hudson ◽  
L D Quirke ◽  
S B Lawrence ◽  
...  
Keyword(s):  
Growth Factors ◽  
Point Mutations ◽  
Follicular Development ◽  
Cumulus Cells ◽  
Ovulation Rate ◽  
Growth Stages ◽  
New Paradigm ◽  
Protein Conjugates ◽  
Preovulatory Follicles

Ovulation rate in mammals is determined by a complex exchange of hormonal signals between the pituitary gland and the ovary and by a localised exchange of hormones within ovarian follicles between the oocyte and its adjacent somatic cells. From examination of inherited patterns of ovulation rate in sheep, point mutations have been identified in two oocyte-expressed genes, BMP15 (GDF9B) and GDF9. Animals heterozygous for any of these mutations have higher ovulation rates (that is, + 0.8–3) than wild-type contemporaries, whereas those homozygous for each of these mutations are sterile with ovarian follicular development disrupted during the preantral growth stages. Both GDF9 and BMP15 proteins are present in follicular fluid, indicating that they are secreted products. In vitro studies show that granulosa and/or cumulus cells are an important target for both growth factors. Multiple immunisations of sheep with BMP15 or GDF9 peptide protein conjugates show that both growth factors are essential for normal follicular growth and the maturation of preovulatory follicles. Short-term (that is, primary and booster) immunisation with a GDF9 or BMP15 peptide-protein conjugate has been shown to enhance ovulation rate and lamb production. In summary, recent studies of genetic mutations in sheep highlight the importance of oocyte-secreted factors in regulating ovulation rate, and these discoveries may help to explain why some mammals have a predisposition to produce two or more offspring rather than one.

scholarly journals The conflict between hierarchical ovarian follicular development and superovulation treatment

Reproduction ◽  
2010 ◽  
Vol 140 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Kenneth P McNatty ◽  
Derek A Heath ◽  
Norma L Hudson ◽  
Karen L Reader ◽  
Laurel Quirke ◽  
...  
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Follicular Development ◽  
Follicular Phase ◽  
Ovulation Rate ◽  
Cell Populations ◽  
Antral Follicles ◽  
Functional States ◽  
Ovarian Follicular Development

In mammals with a low ovulation rate phenotype, ovarian follicular development is thought to be hierarchical with few, if any, antral follicles at similar stages of development. The hypothesis being tested herein was that if most follicles are in a functionally different state, then the application of exogenous hormones to increase ovulation rate will not overcome the hierarchical nature of follicular development. Using sheep as the experimental model, the functional states of all non-atretic antral follicles ≥2 mm diameter were assessed in individual ewes (N=10/group) during anoestrus with or without pregnant mare's serum gonadotrophin (PMSG) treatment, or after a standard superovulation regimen, or during the follicular phase of the oestrous cycle. The functional states of these follicles were assessed by measuring the FSH- or human chorionic gonadotrophin (hCG)-induced cAMP responses of granulosa cellsin vitro. There were significant overall effects across the treatment groups on the responses of granulosa cells to either FSH or LH (bothP<0.001). It was concluded that for anoestrous ewes with or without PMSG treatment, and ewes during the follicular phase, granulosa cell populations of many follicles (≥2 mm diameter) did not share a similar cAMP response to FSH (∼50% of follicles) or hCG (>90% of follicles) either on a per cell or total cell basis. After superovulation, ≤30 and 10% respectively of the granulosa cell populations shared similar responses to FSH and LH with regard to follicular diameter and cAMP output. Thus, exogenous hormone treatments used routinely for increasing oocyte yield do not effectively override the hierarchical pattern of ovarian follicular development during the follicular phase.

scholarly journals AKT is involved in granulosa cell autophagy regulation via mTOR signaling during rat follicular development and atresia

Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. 73-80 ◽  
Author(s):  
JongYeob Choi ◽  
MinWha Jo ◽  
EunYoung Lee ◽  
DooSeok Choi
Keyword(s):  
Cell Death ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Apoptotic Cell ◽  
Follicular Development ◽  
Negative Regulator ◽  
Metabolic Clearance ◽  
Akt Inhibitor ◽  
Western Blots

In this study, we examined whether granulosa cell autophagy during follicular development and atresia was regulated by the class I phosphoinositide-3 kinase/protein kinase B (AKT) pathway, which is known to control the activity of mammalian target of rapamycin (mTOR), a major negative regulator of autophagy. Ovaries and granulosa cells were obtained using an established gonadotropin-primed immature rat model that induces follicular development and atresia. Autophagy was evaluated by measuring the expression level of microtubule-associated protein light chain 3-II (LC3-II) using western blots and immunohistochemistry. The activity of AKT and mTOR was also examined by observing the phosphorylation of AKT and ribosomal protein S6 kinase (S6K) respectively. After gonadotropin injection, LC3-II expression was suppressed and phosphorylation of AKT and S6K increased in rat granulosa cells. By contrast, gonadotropin withdrawal by metabolic clearance promoted LC3-II expression and decreased phosphorylation of AKT and S6K. In addition,in-vitroFSH treatment of rat granulosa cells also indicated inhibition of LC3-II expression accompanied by a marked increase in phosphorylation of AKT and S6K. Inhibition of AKT phosphorylation using AKT inhibitor VIII suppressed FSH-mediated phosphorylation of S6K, followed by an increase in LC3-II expression. Furthermore, co-treatment with FSH and AKT inhibitor increased the levels of apoptosis and cell death of granulosa cells compared with the single treatment with FSH. Taken together, our findings indicated that AKT-mediated activation of mTOR suppresses granulosa cell autophagy during follicular development and is involved in the regulation of apoptotic cell death.

Identification of Gαs messenger ribonucleic acid splice variants in human granulosa cells

1997 ◽  
Vol 18 (1) ◽  
pp. 27-35 ◽  
Author(s):  
G N Europe-Finner ◽  
E Cartwright ◽  
J Bellinger ◽  
H J Mardon ◽  
D H Barlow ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Ovarian Function ◽  
Splice Variants ◽  
Consensus Sequence ◽  
Phosphorylation Site ◽  
Follicular Development ◽  
Protein Isoforms ◽  
Mrna Isoforms ◽  
Messenger Ribonucleic Acid

ABSTRACT Granulosa cells are essential for follicular development and corpus luteum formation and their functions are regulated by gonadotrophins through G protein-coupled receptors. The dominant second messenger pathway involves the stimulation of cyclic AMP formation by Gαs-linked receptors. In this paper we have investigated the expression of Gαs mRNA splice variants in relation to expression of Gαs protein isoforms in granulosa cells obtained from patients undergoing in vitro fertilization. We have carried out ribonuclease protection assays using cRNA riboprobes which are capable of detecting all Gαs mRNA isoforms as well as quantifying total amounts of Gαs mRNA. Granulosa cells express the message for Gαs-Large and Gαs-Small and the presence of two distinct protein products was confirmed by immunoblotting using the antibody RM/1. Moreover, the data show that a significant fraction of Gαs-Large and Gαs-Small mRNAs contain an extra CAG codon. This should generate proteins with an extra serine residue, resulting in Gαs variants with the consensus sequence of a protein kinase C phosphorylation site. These results highlight the possible interaction between different signalling pathways in the control of cAMP production and the need to investigate the relationship between Gαs variants and different adenylyl cyclase isozymes in patients with normal and abnormal ovarian function.

scholarly journals Pentachloronitrobenzene alters progesterone production and primordial follicle recruitment in cultured granulosa cells and rat ovary†

2019 ◽  
Vol 102 (2) ◽  
pp. 511-520
Author(s):  
Yanrong Kuai ◽  
Xiaobo Gao ◽  
Huixia Yang ◽  
Haiyan Luo ◽  
Yang Xu ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Granulosa Cells ◽  
Crop Production ◽  
Follicular Development ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Serum Progesterone ◽  
Primordial Follicles ◽  
Progesterone Production

Abstract Pentachloronitrobenzene (PCNB) is an organochlorine fungicide widely used for crop production and has become an environmental concern. Little is known about the effect of PCNB on ovarian steroidogenesis and follicular development. We found that PCNB stimulated Star expression and progesterone production in cultured rat granulosa cells in a dose-dependent manner. PCNB activated mitogen-activated protein kinase (MAPK3/1) extracellulat regulated kinase (ERK1/2), thus inhibition of either protein kinase A (PKA) or MAPK3/1 signaling pathway significantly attenuated progesterone biosynthesis caused by PCNB, suggesting that PCNB induced progesterone production by activating the cyclic adenosine monophosphate (cAMP/PKA) and MAPK3/1 signaling pathways. Further investigation demonstrated that PCNB induced Star expression and altered MAPK3/1 signaling in ovary tissues of immature SD rats treated with PCNB at the dose of 100, 200, or 300 mg/kg by daily gavage for 7 days, while serum progesterone level was dose-dependently decreased. We demonstrated that PCNB exposure accelerated the recruitment of primordial follicles into the growing follicle pool in ovary tissues, accompanied by increased levels of anti-Mullerian hormone (AMH) in both ovary tissues and serum. Taken together, our data demonstrate for the first time that PCNB stimulated Star expression, altered MAPK3/1 signaling and progesterone production in vivo and in vitro, and accelerated follicular development with a concomitant increase in AMH in ovary tissues and serum. Our findings provide novel insight into the toxicity of PCNB to animal ovary function.

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 The Phytoestrogen Quercetin Impairs Steroidogenesis and Angiogenesis in Swine Granulosa Cells In Vitro

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Sujen Eleonora Santini ◽  
Giuseppina Basini ◽  
Simona Bussolati ◽  
Francesca Grasselli
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Follicular Development ◽  
Redox Status ◽  
Negative Influence ◽  
Animal Nutrition ◽  
Follicle Development ◽  
Vascular Endothelial ◽  
Endothelial Growth Factor

Experimental evidence documents that nutritional phytoestrogens may interact with reproductive functions but the exact mechanism of action is still controversial. Since quercetin is one of the main flavonoids in livestock nutrition, we evaluated its possible effects on cultured swine granulosa cell proliferation, steroidogenesis, and redox status. Moreover, since angiogenesis is essential for follicle development, the effect of the flavonoid on Vascular Endothelial Growth Factor output by granulosa cells was also taken into account. Our data evidence that quercetin does not affect granulosa cell growth while it inhibits progesterone production and modifies estradiol production in a dose-related manner. Additionally, the flavonoid interferes with the angiogenic process by inhibiting VEGF production as well as by altering redox status. Since steroidogenesis and angiogenesis are strictly involved in follicular development, these findings appear particularly relevant, pointing out a possible negative influence of quercetin on ovarian physiology. Therefore, the possible reproductive impact of the flavonoid should be carefully considered in animal nutrition.

scholarly journals miR-375 mediates CRH signaling pathway in inhibiting E2 synthesis in porcine ovary

Reproduction ◽  
2017 ◽  
Vol 153 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Chulin Yu ◽  
Meiling Li ◽  
Yue Wang ◽  
Ying Liu ◽  
Chengzhi Yan ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Granulosa Cells ◽  
Reproductive System ◽  
Follicular Development ◽  
Cell Types ◽  
Signaling System ◽  
Key Factor ◽  
The Relationship

The corticotropin-releasing hormone (CRH) signaling system is involved in numbers of stress-related physiological and pathological responses, including its inhibiting effects on estradiol (E2) synthesis and follicular development in the ovary. In addition, there are reports that microRNAs (miRNAs) can control the function of animal reproductive system. The aim of present study was to investigate the functions of miR-375 and the relationship between miR-375 and CRH signaling molecules in the porcine ovary. First, our common PCR results show that miR-375 and the CRH receptor 1 (CRHR1) are expressed in porcine ovary, whereas CRH receptor 2 (CRHR2) is not detected. We further have located the cell types of miR-375 and CRHR1 by in situ hybridization (ISH), and the results show that miR-375 is located only in the granulosa cells, whereas CRHR1 is positive in all of granulosa cells and oocytes, inferring that miR-375 and CRHR1 are co-localized in granulosa cells. Second, we show that overexpression of miR-375 in cultured granulosa cells suppresses the E2 production, whereas miR-375 knockdown demonstrates the opposite result. Besides, our in vitro results demonstrate that miR-375 mediates the signaling pathway of CRH inhibiting E2 synthesis. Finally, our data show that the action of miR-375 is accomplished by directly binding to the 3′UTR of specificity protein1 (SP1) mRNA to decrease the SP1 protein level. Thus, we conclude that miR-375 is a key factor in regulating E2 synthesis by mediating the CRH signaling pathway.

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