scholarly journals Gonadotropin-dependent regulation of bovine pituitary adenylate cyclase-activating polypeptide in ovarian follicles prior to ovulation

Reproduction ◽  
2007 ◽  
Vol 133 (2) ◽  
pp. 441-453 ◽  
Author(s):  
Khampoune Sayasith ◽  
Kristy A Brown ◽  
Jean Sirois
Keyword(s):  
Adenylate Cyclase ◽  
Granulosa Cells ◽  
Cell Types ◽  
Rt Pcr ◽  
Reading Frame ◽  
Chain Cleavage ◽  
Acid Protein ◽  
Pituitary Adenylate Cyclase ◽  
Preovulatory Follicles ◽  
Ep2 Receptor

To study the regulation of bovine pituitary adenylate cyclase-activating polypeptide (PACAP) in preovulatory follicles prior to ovulation, PACAP cDNA was isolated by RT-PCR. Its open reading frame (ORF) is composed of 531 bp, and encodes for a 176-amino acid protein that bears 76–90% identity with other PACAP homologs. Using bovine preovulatory follicles obtained between 0 and 24 h after human chorionic gonadotropin (hCG) and semiquantitative RT-PCR/Southern blot, we demonstrate that levels of PACAP mRNA were low at 0 h, markedly increased at 6 and 12 h (P<0.05), and declined 18 and 24 h after hCG. Levels of PACAP mRNA were high in the bovine pituitary, testis, intestine and uterus, but moderate to low in other tissues. Analyses performed on isolated preparations of granulosa and theca cells showed a significant increase of PACAP transcripts in both cell types after hCG, whereas primary granulosa cell cultures revealed high levels of PACAP as well as its receptors PAC-1 and VPAC-2 mRNA after forskolin treatment. Overexpression of the catalytic subunit of protein kinase A (PKA) in granulosa cells stimulated, but treatment with H89 or PKA inhibitor protein inhibited PACAP mRNA expression, whereas PACAP overexpression stimulated an increase in abundance of transcripts for PGHS-2, PGES, EP2 receptor, progesterone receptor, and ADAMTS-1, but not for P450-side chain cleavage and P450 aromatase. Thus, this study demonstrates the gonadotropin-dependent regulation of PACAP mRNA in bovine preovulatory follicles, the importance of PKA activation in the expression of PACAP in granulosa cells, and stimulating effect of PACAP on gene expression during the ovulatory process.

scholarly journals Cloning of equine prostaglandin dehydrogenase and its gonadotropin-dependent regulation in theca and mural granulosa cells of equine preovulatory follicles during the ovulatory process

Reproduction ◽  
2007 ◽  
Vol 133 (2) ◽  
pp. 455-466 ◽  
Author(s):  
Khampoune Sayasith ◽  
Nadine Bouchard ◽  
Monique Doré ◽  
Jean Sirois
Keyword(s):  
Granulosa Cells ◽  
Cell Types ◽  
Primate Species ◽  
Rt Pcr ◽  
Reading Frame ◽  
Preovulatory Follicles ◽  
Prostaglandin Dehydrogenase ◽  
Rapid Amplification ◽  
Species Specific ◽  
Ovulatory Process

The mammalian ovulatory process is accompanied by a gonadotropin-dependent increase in follicular levels of prostaglandin E2 (PGE2) and PGF2α, which are metabolized by 15-hydroxy prostaglandin dehydrogenase (PGDH). Little is known about ovarian PGDH regulation in non-primate species. The objectives of this study were to characterize the structure of equine PGDH and its regulation in follicles during human chorionic gonadotropin (hCG)-induced ovulation. The full-length equine PGDH was obtained by RT-PCR, 5′- and 3′-rapid amplification of cDNA ends (RACE). Its open reading frame encodes a 266-amino acid protein that is 72–95% homologous to other species. Semi-quantitative RT-PCR/Southern blot were used to study PGDH regulation in follicles isolated 0–39 h post-hCG. Results showed that PGDH mRNA expression was low in follicles obtained at 0 h, increased at 12 and 24 h (P< 0.05), and decreased at 36-h post-hCG. This induction of expression was biphasic, with elevated abundance of transcripts at 12 and 33 h post-hCG (P< 0.05) in mural granulosa and theca cells. Immunohistochemistry and immunoblotting confirmed regulated expression of PGHD protein in both cell types of preovulatory follicles after hCG. High levels of PGDH mRNA were observed in corpus luteum and other non-ovarian tissues tested, except kidney, muscle, brain, and heart. Thus, this study is the first to report the gonadotropin-dependent regulation of PGDH during ovulation in a non-primate species. PGDH induction was biphasic in theca and mural granulosa cells differing from primates in which this induction was monophasic and limited to granulosa cells, suggesting species-specific differences in follicular control of PGDH expression during ovulation.

scholarly journals Expression localisation and functional activity of pituitary adenylate cyclase-activating polypeptide, vasoactive intestinal polypeptide and their receptors in mouse ovary

Reproduction ◽  
2007 ◽  
Vol 134 (2) ◽  
pp. 281-292 ◽  
Author(s):  
Marzia Barberi ◽  
Barbara Muciaccia ◽  
Maria Beatrice Morelli ◽  
Mario Stefanini ◽  
Sandra Cecconi ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Vasoactive Intestinal Polypeptide ◽  
Granulosa Cells ◽  
Ovarian Tissue ◽  
Type I ◽  
Mouse Ovary ◽  
Vip Receptors ◽  
Pituitary Adenylate Cyclase ◽  
Preovulatory Follicles ◽  
Intestinal Polypeptide

Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) positively affect several parameters correlated with the ovulatory process. PACAP is transiently expressed in rat preovulatory follicles, while VIP is present in nerve fibres at all stages of development. These two peptides act by interacting with three types of receptors: PACAP type I receptor (PAC1-R), which binds with higher affinity to PACAP, and two VIP receptors (VPAC1-R and VPAC2-R), which bind to PACAP and VIP with equal affinity. The aim of the present study was to characterise the PACAP/VIP/receptor system in the mouse ovary. Results obtained by RT-PCR, immunohistochemistry and in situ hybridisation showed that PACAP was transiently expressed in granulosa cells of preovulatory follicles after human chorionic gonadotrophin (hCG) stimulation, while VIP mRNA was never observed. All the receptors were present in 22-day-old untreated mice. In preovulatory follicles, PAC1-R was expressed both in granulosa cells and in residual ovarian tissue but was stimulated by hCG mainly in granulosa cells; VPAC2-R was present in both the cell compartments and was only mildly stimulated; VPAC1-R was present mainly in the residual ovarian tissue and was downregulated by hCG. PACAP and VIP were equipotent in inhibiting apoptosis in granulosa cells, confirming the presence of functional PACAP/VIP receptors. The contemporary induction by hCG of PACAP and PAC1-R in granulosa cells of preovulatory follicles suggests that, also in mouse ovary, PACAP may play a significant role around the time of ovulation. Moreover, the presence of PACAP/VIP receptors in the untreated ovary suggests a possible role for PACAP and VIP during follicle development.

scholarly journals Characterization and expression of different pituitary adenylate cyclase-activating polypeptide/vasoactive intestinal polypeptide receptors in rat ovarian follicles

2006 ◽  
Vol 191 (1) ◽  
pp. 287-299 ◽  
Author(s):  
Sergio Vaccari ◽  
Stefania Latini ◽  
Marzia Barberi ◽  
Anna Teti ◽  
Mario Stefanini ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Vasoactive Intestinal Polypeptide ◽  
Granulosa Cells ◽  
Type I ◽  
Vip Receptors ◽  
Pituitary Adenylate Cyclase ◽  
Preovulatory Follicles ◽  
Stimulation Of ◽  
Whole Ovaries ◽  
Intestinal Polypeptide

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a bioactive peptide transiently expressed in preovulatory follicles. PACAP acts by interacting with three types of PACAP receptors. PACAP type I receptor (PAC1-R), which binds specifically to both PACAPs and vasoactive intestinal polypeptide (VIP), although with lower affinity, and two VIP receptors, VPAC1-R and VPAC2-R, which bind to PACAP and VIP with equal affinity. In the present study, we showed the expression of all three receptors in whole ovaries obtained from juvenile and gonadotropin-treated immature rats. A more detailed analysis on cells from preovulatory follicles showed that PAC1-R and VPAC2-R were expressed in granulosa cells, whereas only VIP receptors were expressed in theca/interstitial (TI) cells and fully grown oocytes presented only PAC1-R. The distribution of the VIP receptors was confirmed by immunofluorescence. HCG treatment induced stimulation of PAC1-R in granulosa cells and VPAC2-R in TI cells. The presence of functional PACAP/VIP receptors was also supported by metabolic studies. We further evaluated the presence of PACAP and VIP receptors by testing the effect of these peptides on apoptosis in granulosa cells cultured, isolated or in whole follicles. Treatment of follicles with PACAP and VIP dose-dependently inhibited apoptosis, while only PACAP significantly inhibited isolated granulosa cells. These results demonstrate a different expression of PACAP/VIP receptors in the various follicle compartments and suggest a possible role for PACAP and VIP on granulosa and TI cells, both during follicle development and ovulation.

scholarly journals Characterization of bovine early growth response factor-1 and its gonadotropin-dependent regulation in ovarian follicles prior to ovulation

2006 ◽  
Vol 37 (2) ◽  
pp. 239-250 ◽  
Author(s):  
Khampoune Sayasith ◽  
Kristy A Brown ◽  
Jacques G Lussier ◽  
Monique Doré ◽  
Jean Sirois
Keyword(s):  
Cytochrome P450 ◽  
Granulosa Cells ◽  
Growth Response ◽  
Cell Types ◽  
Early Growth ◽  
Response Factor ◽  
Coding Region ◽  
Rt Pcr ◽  
Early Growth Response ◽  
Preovulatory Follicles

Early growth response factor-1 (EGR-1) is a transcription factor that is involved in the transactivation of several genes. The objective of this study was to characterize gonadotropin-dependent regulation of bovine EGR-1 in preovulatory follicles prior to ovulation. Bovine EGR-1 cDNA was obtained by RT-PCR, 5′- and 3′-RACE, its open reading frame composed of 1623 bp, and its coding region encodes a 540-amino acid protein that displays 62–93% identity to known mammalian homologs. The regulation of EGR-1 mRNA was studied in bovine preovulatory follicles which were isolated 0–24 h post-hCG using semiquantitative RT-PCR/Southern blot. Results revealed that the levels of EGR-1 mRNA were very low in follicles at 0 h, markedly increased at 6 h (P < 0.05) when compared to 0 h, and decreased between 12 and 24 h post-hCG. High levels of the EGR-1 mRNA were also observed in corpus luteum, uterus, kidney, pituitary, and spleen, moderate and low in other bovine tissues tested. Analyses performed on isolated preparations of granulosa and theca cells indicated that EGR-1 mRNA was regulated in both cell types, with a predominant expression in granulosa cells. Immunohistochemistry on sections of preovulatory follicles isolated before and after hCG confirmed its protein expression in granulosa cells, 24 h post-hCG. Studies of EGR-1 regulation in primary granulosa cells cultured with forskolin showed that levels of EGR-1 mRNA were low at 0 h, highly increased at 6 h post-forskolin (P < 0.05), and declined to steady state thereafter. Immunoblotting confirmed forskolin-induced EGR-1 protein in cultures. Interestingly, overexpression of EGR-1 increased the levels of mRNA for prostaglandin (PG) G/H synthase-2 (PGHS-2), PG E synthase (PGES), PG E2 receptor (EP2), LH receptor (LH-R), but not for cytochrome P450-side chain cleavage (P450scc), and cytochrome P450 aromatase (P450arom) in granulosa cultures. Thus, this study reports for the first time, a gonadotropin-dependent induction of follicular EGR-1 prior to ovulation in large monoovulatory species and its stimulating effect on the expression of genes known to be involved in prostaglandin biosynthesis pathway, thereby suggesting its potential involvement in the regulation of preovulatory events in cattle.

scholarly journals Pituitary Adenylate Cyclase-Activating Polypeptide Protects Glomerular Podocytes from Inflammatory Injuries

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Kenichi Sakamoto ◽  
Kyoko Kuno ◽  
Minoru Takemoto ◽  
Peng He ◽  
Takahiro Ishikawa ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Treatment Options ◽  
Cell Types ◽  
Specific Cell ◽  
Monocyte Chemoattractant Protein 1 ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Pituitary Adenylate Cyclase ◽  
End Stage ◽  
Anti Inflammation

Diabetic nephropathy (DN) is a leading cause of end-stage kidney disease; however, there are few treatment options. Inflammation plays a crucial role in the initiation and/or progression of DN. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide, which was originally isolated from the ovine hypothalamus and reportedly has diverse biological functions. It has been reported that PACAP has renoprotective effects in different models of kidney pathology. However, the specific cell types within the kidney that are protected by PACAP have not yet been reported. In this study, we localized VPAC1, one of the PACAP receptors, to glomerular podocytes, which also reportedly has crucial roles not only in glomerular physiology but also in pathology. PACAP was effective in the downregulation of proinflammatory cytokines, such as monocyte chemoattractant protein-1 (MCP-1) and interleukin-6, which had been induced by the activation of toll-like receptor (TLR) with lipopolysaccharide. PACAP also had downregulated the expression of MCP-1 through the protein kinase A signaling pathway; this led to the attenuation of the activation of extracellular signal-regulated kinase and nuclear factor-kappa B signaling. Our results suggested that PACAP could be a possible treatment option for DN through the use of anti-inflammation effects on glomerular podocytes.

scholarly journals Human Chorionic Gonadotropin-Dependent Up-Regulation of Genes Responsible for Estrogen Sulfoconjugation and Export in Granulosa Cells of Luteinizing Preovulatory Follicles

Endocrinology ◽  
2006 ◽  
Vol 147 (9) ◽  
pp. 4222-4233 ◽  
Author(s):  
Kristy A. Brown ◽  
Monique Doré ◽  
Jacques G. Lussier ◽  
Jean Sirois
Keyword(s):  
Chorionic Gonadotropin ◽  
Granulosa Cells ◽  
Human Chorionic Gonadotropin ◽  
Cell Layer ◽  
Rt Pcr ◽  
Expression Of Genes ◽  
Preovulatory Follicles ◽  
Steady State Levels ◽  
17Β Estradiol ◽  
Theca Interna

Estrogen sulfotransferase (EST) is responsible for the sulfoconjugation of estrogens, thereby changing their physical properties and preventing their action via the estrogen receptors. These sulfoconjugated steroids no longer diffuse freely across the lipid bilayer; instead, they are exported by members of the ATP-binding cassette family, such as ABCC1. The objective of this study was to investigate the regulation of EST and ABCC1 during human chorionic gonadotropin (hCG)-induced ovulation/luteinization. The transcripts for EST and ABCC1 were cloned by RT-PCR, and the regulation of their mRNAs was studied in preovulatory follicles obtained during estrus at 0, 12, 24, 30, 33, 36, and 39 h after hCG. Results obtained from RT-PCR/Southern blot analyses showed significant changes in steady-state levels of both EST and ABCC1 mRNA after hCG treatment (P &lt; 0.05). In granulosa cells, a significant increase in EST transcript was observed 30–39 h after hCG. Similarly, ABCC1 transcript levels were induced in granulosa cells 12–39 h after hCG. In contrast, no significant changes in either EST or ABCC1 were detected in theca interna samples after hCG. The increase in EST and ABCC1 transcripts observed in granulosa cells was reflected in preparations of intact follicle walls, suggesting that the granulosa cell layer contributes the majority of EST and ABCC1 expression in preovulatory follicles. The present study demonstrates that follicular luteinization is accompanied not only by a decrease in 17β-estradiol biosynthesis but also by an increase in expression of genes responsible for estrogen inactivation and elimination from granulosa cells, such as EST and ABCC1, respectively.

Secretion of 17α-hydroxyprogesterone, androstenedione, and estrogens by porcine granulosa and theca interna cells in culture

1987 ◽  
Vol 65 (9) ◽  
pp. 1951-1956 ◽  
Author(s):  
Benjamin K. Tsang ◽  
Arezoo Taheri ◽  
Louis Ainsworth ◽  
Bruce R. Downey
Keyword(s):  
Granulosa Cells ◽  
Cell Types ◽  
High Yield ◽  
Aromatase Activity ◽  
Steroid Substrate ◽  
Preovulatory Follicles ◽  
Serum Gonadotropin ◽  
Exogenous Progesterone ◽  
Theca Interna ◽  
Estradiol 17Β

The steroid secreting activities of dispersed granulosa and theca interna cells from preovulatory follicles of prepubertal gilts 72 h after pregnant mare's serum gonadotropin treatment (750 IU) were compared. The cells were cultured for 24 h with or without steroid substrate (10−8 to 10−5 M progesterone, 17α-hydroxyprogesterone, or androstenedione), FSH (100 ng/mL), LH (100 ng/mL), and cyanoketone (0.25 μM, an inhibitor of 3β-hydroxysteroid dehydrogenase). Granulosa cells cultured alone secreted mainly progesterone. Theca interna cells secreted mainly 17α-hydroxyprogesterone and androstenedione, with secretion being markedly enhanced by LH. In the presence of cyanoketone, which inhibited endogenous progesterone production, theca interna but not granulosa cells were able to convert exogenous progesterone to 17α-hydroxyprogesterone and androstenedione, and exogenous 17α-hydroxyprogesterone to androstenedione and estradiol-17β in high yield. The secretion of the latter steroids from exogenous substrates was unaffected by LH. Theca interna cells secreted more estradiol-17β than did granulosa cells in the absence of aromatizable substrate, but estradiol-17β secretion by the latter was markedly increased after the addition of androstenedione. These apparent differences in steroid secreting activity between the cell types suggest that the enzymes responsible for conversion of C21 to C19 steroids, i.e., 17α-hydroxylase and C17,20-lyase, reside principally in the theca interna cells. However, aromatase activity appears to be much higher in granulosa cells.

scholarly journals Localization of gonadotrophin-releasing hormone I, bradykinin and their receptors in the ovaries of non-mammalian vertebrates

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 969-981 ◽  
Author(s):  
Padmasana Singh ◽  
Amitabh Krishna ◽  
Rajagopala Sridaran
Keyword(s):  
Granulosa Cells ◽  
Follicular Development ◽  
Cell Types ◽  
Physiological Significance ◽  
Rt Pcr ◽  
Releasing Hormone ◽  
Theca Cells ◽  
Gonadotrophin Releasing Hormone

GnRH I and its receptors have been demonstrated in the ovaries of various vertebrates, but their physiological significance in reproductive cascade is fragmentary. Bradykinin is a potent GnRH stimulator in the hypothalamus. In the present study, the presence of GnRH I and its receptor, and bradykinin and its receptor in the ovaries of non-mammalian vertebrates were investigated to understand their physiological significance. GnRH I immunoreactivity in the ovaries of fish, frog, reptile and bird were mainly found in the oocyte of early growing follicles and granulosa cells and theca cells of previtellogenic follicles. Vitellogenic follicles showed mild GnRH immunoreactivity. GnRH I-receptor and bradykinin were localized in the same cell types of the ovaries of these vertebrates. The presence of GnRH I, GnRH I-receptor and bradykinin in the ovaries of these vertebrates was confirmed by immunoblotting. The presence of GnRH I mRNA was demonstrated in the ovary of vertebrates using RT-PCR. The ovaries of reptiles and birds showed significantly higher intensity of immunoreactivity for GnRH I-receptor as compared with the fish and amphibian. This may have a correlation with the higher yolk content in the ovary of reptile and bird. These results suggest the possibility of GnRH I and bradykinin as important regulators of follicular development and vitellogenesis in the vertebrate ovary.

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