NCBI Summary:
This gene encodes a secreted proprotein that is further processed into multiple mature peptides. These peptides stimulate adenylate cyclase and increase cyclic adenosine monophosphate (cAMP) levels, resulting in the transcriptional activation of target genes. The products of this gene are key mediators of neuroendocrine stress responses. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2013]
The use of pituitary adenylate cyclase-activating polypeptide (PACAP) for the application of pre-maturation system improves in vitro developmental competence from small follicles of porcine oocytes. Park KM et al. (2019) We investigated how pituitary adenylate cyclase-activating polypeptide (PACAP) affects on embryonic development during pre-in vitro maturation (pre-IVM) using porcine oocytes isolated from small follicles. We divided the follicles into the experimental groups by size (SF; small follicles, MF; medium follicles) and treated with and without PACAP and cultured for 18 hours Pre-SF(-)PACAP; without PACAP, Pre-SF(+)PACAP; with PACAP] before undergoing in vitro maturation (IVM). The gene expression related to extracellular matrix formation (AREG, EREG and HAS2) and apoptosis (BAX, BCL-2 and CASPASE-3) was investigated after maturation. The impact on developmental competence was assessed by the cleavage and blastocyst rate and total cell number of blastocyst in embryos generated from parthenogenesis (PA) and in vitro fertilization (IVF). Cleavage rates in the Pre-SF(+)PACAP after PA were significantly higher than SF and Pre-SF(-)PACAP (p<0.05). The cleavage rates between MF and Pre- SF(+)PACAP groups yielded no notable differences after IVF. Pre-SF(+)PACAP displayed the higher rate of blastocyst formation and greater total cell number than SF and Pre-SF(-)PACAP (p<0.05). Cumulus cells showed significant upregulation of HAS2 mRNA in the Pre-SF(+)PACAP compared to the SF (p<0.05). In comparison to other groups, the Pre-SF(+)PACAP group displayed a downregulation in mRNA expression of BAX in matured oocytes (p<0.05). PACAP treatment during pre-IVM improved the developmental potential of porcine oocytes derived from small follicles by regulating cumulus expansion and apoptosis of oocytes.//////////////////Gonadotropin stimulation of pituitary adenylate cyclase-activating polypeptide (PACAP) messenger ribonucleic acid in the rat ovary and the role of PACAP as a follicle survival factor. [Lee J 1999 et al.
Pituitary adenylate cyclase-activating polypeptide (PACAP), a novel neuropeptide with considerable homology to vasoactive intestinal peptide and GH-releasing hormone, exists in two biologically active forms, PACAP-38 and -27. The presence of PACAP in the ovary has been demonstrated, where it stimulates steroidogenesis and cAMP accumulation in cultured granulosa cells. In the present study, gonadotropin regulation of PACAP gene expression was examined in PMSG/human (h)CG-treated immature rat ovaries and cultured preovulatory follicles. Northern blot analysis of ovaries obtained from PMSG/hCG-treated immature animals revealed the transient induction of PACAP transcripts by hCG, reaching a maximum at 6 h. The major cell types expressing PACAP messenger RNA were granulosa cells of preovulatory follicles and some theca/interstitial cells. In preovulatory follicles cultured in serum-free medium, PACAP transcripts were transiently induced by LH and FSH, reaching a maximum 6-9 h after stimulation in granulosa cells but not in theca cells. Treatment with cycloheximide or alpha-amanitin abolished LH-induced PACAP transcripts, indicating that new protein synthesis and transcription are necessary. Treatment with MDL-12,330A, an inhibitor of adenylate cyclase, inhibited LH-induced PACAP messenger RNA, and forskolin mimicked the LH action, implying the role of adenylate cyclase activation. In contrast, treatment with chelerythrine, an inhibitor of protein kinase C, and 2-O-tetradecanol-phorbol-13-acetate had no effect. We further tested the role of PACAP in follicle apoptosis using apoptotic DNA fragmentation analysis. Treatment with PACAP-38 suppressed follicle apoptosis in a dose-dependent manner. Moreover, the LH suppression of follicle apoptosis was partially blocked by cotreatment with PACAP-38 antagonist, indicating mediation by endogenous PACAP-38. These results suggest that PACAP, transiently induced by the gonadotropin surge, could be a local regulator of a number of events and may act as a follicle survival factor during the periovulatory period.
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Expression and functional activity of PACAP and its receptors on cumulus cells: effects on oocyte maturation. Barberi M et al. Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor PAC1-R (PACAP type 1 receptor) are transiently expressed in granulosa cells (GCs) of mouse preovulatory follicles and affect several parameters associated with the ovulatory process. We investigated the expression of PACAP and its receptors in cumulus cells (CCs) after the LH surge and their role on cumulus expansion/apoptosis and oocyte maturation. PACAP and PAC1-R expression increased in CCs isolated at different times after treatment with human chorionic gonadotropin (hCG). Moreover, PACAP was able to reverse the inhibition of oocyte meiotic maturation caused by hypoxantine in cumulus cell-oocyte complexes (COCs) and efficiently promoted male pronuclear formation after fertilisation. PACAP was also able to induce cumulus expansion and prevent CC apoptosis. Our results demonstrated the induction of PACAP and its receptors in CCs by LH and EGF, suggesting that PACAP may play a significant role in the complex interactions of gonadotropin and growth factors during ovulation and fertilisation.
Inhibitory effect of pituitary adenylate cyclase activating polypeptide on the initial stages of rat follicle development. Latini S et al. Pituitary adenylate cyclase activating polypeptide (PACAP) is transiently expressed in preovulatory follicles of different species and positively affects parameters correlated with the ovulatory process. It has also been shown to be expressed in the interstitial tissue and in interstitial glandular cells in the proximity of primordial and preantral follicles. The aim of the present study was to investigate whether PACAP influences the recruitment of primordial follicles and the growth and differentiation of preantral follicles. Rat ovaries from 2-day-old animals were cultured for 5 days in the presence of PACAP. This treatment significantly inhibited the primordial to primary follicle transition. PACAP inhibited granulosa cell proliferation without affecting cell viability. PACAP also inhibited the growth of isolated preantral follicles cultured under basal conditions or in the presence of follicle-stimulating hormone (FSH). These results suggest that PACAP is significantly involved in the cyclic recruitment of primordial follicles and in the FSH-dependent growth of preantral follicles.
Pituitary adenylate cyclase-activating peptide stimulates acute progesterone production in rat granulosa/Lutein cells via two receptor subtypes Gras S, et al .
Pituitary adenylate cyclase-activating peptide (PACAP) is transiently expressed in ovarian granulosa/lutein cells from eCG/hCG-treated rats, and in vitro immunoneutralization of endogenously released PACAP inhibits acute progesterone secretion and subsequent luteinization in such cells. This suggests that PACAP mediates locally some of the effects of the LH surge, but the putative PACAP receptor(s) involved in such an auto or paracrine activity is presently unknown. Reverse-transcription polymerase chain reaction with specific primers to the three cloned PACAP-binding receptors called PAC(1), VPAC(1), and VPAC(2) demonstrated both PAC(1) and VPAC(2) mRNA in extracts from preovulatory follicular cells. Radioligand-binding assays revealed the presence of high-affinity binding sites with characteristics of these two receptors on the intact cells, and autoradiography demonstrated that the binding was restricted to a minor proportion of the follicular cells as well as the oocytes. Pituitary adenylate cyclase-activating peptide and vasoactive intestinal peptide (VIP) dose-dependently stimulated cAMP accumulation and acute progesterone accumulation. Forskolin and db-cAMP also stimulated acute progesterone accumulation, and the protein kinase A inhibitor H89 dose-dependently inhibited peptide induced acute progesterone accumulation, suggesting involvement of cAMP and the protein kinase A pathway in the process. In conclusion, two of the three PACAP binding receptors are present on preovulatory follicular cells and are involved in the effects of PACAP on acute progesterone production. The data provide further evidence to establish PACAP as an auto- or paracrine regulator of LH-induced acute progesterone production in rat preovulatory follicles.
Expression regulated by
LH
Comment
Gonadotropin-dependent regulation of bovine pituitary adenylate cyclase-activating polypeptide in ovarian follicles prior to ovulation. Sayasith K et al. 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.
Ovarian localization
Cumulus, Theca, Luteal cells, Follicular Fluid
Comment
Correlation Between Oocyte Number and Follicular Fluid Concentration of Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) in Women After Superovulation Treatment. Koppan M et al. Follicular growth, ovulation, and luteinization are influenced by interactions of peptide and steroid hormone-signaling cascades in the ovary. Pituitary adenylate cyclase-activating polypeptide (PACAP) plays an important role in the regulation of several endocrine processes and is present in ovarian follicular fluid (FF). However, little is known about PACAP in FF with regard to maturation, ovulation, fertilization, and successful pregnancy. The aim of this pilot study was to investigate whether there is a correlation between PACAP concentration in FF and ovarian response to superovulation treatment in infertile women, performed in volunteers (n?=?132; aged between 20 and 35). After treatment, the number of harvested oocytes was recorded and PACAP immunoreactivity in FF was measured by radioimmunoassay. All the corresponding PACAP concentrations were below 290?fmol/ml in cases when the number of harvested oocytes exceeded 14 per patient, while in all cases above 290?fmol/ml, the number of oocytes was below 14. Using these cutoff values, we determined three study groups: high-PACAP concentration, high-oocyte number, and low-PACAP concentration-low-oocyte number groups. Median values of PACAP concentration in these groups were 411.2, 106.5, and 101.0?fmol/ml, respectively, while the median values of harvested oocytes were 5.5, 19.0, and 5.0, respectively. Differences were significant, indicating a correlation between concentration of PACAP in FF and the number of recruited oocytes. Higher concentrations of PACAP in FF might be associated with lower number of developing oocytes, while low concentrations of PACAP might correlate with a markedly higher number of ova retrieved, thus predicting a higher chance for ovarian hyperstimulation. Our present study is among the first few human clinical studies with direct conclusions drawn for possible clinical impact of PACAP.
This gene was found in an ovarian DNA array.
Kotani E et al reported that rat corpus luteum expresses both PACAP and PACAP type IA receptor mRNAs.
Role of pituitary adenylate cyclase-activating peptide (PACAP) in the cyclic recruitment of immature follicles in the rat ovary.
Gras S, et al 2005 .
Following the midcyclic gonadotropin surge, PACAP is transiently expressed for approximately 12 h in the cyclic adult rat ovary. PACAP is observed in granulosa/lutein cells of the large mature follicles destined to ovulate and is believed to be a regulator of acute progesterone production and luteinization in these follicles. PACAP is also observed in solitary theca cells of immature follicles and in interstitial glandular cells intimately surrounding immature follicles. To examine if PACAP could be involved in the process of cyclic recruitment of such immature follicles, we primed immature granulosa cells from prepubertal ovaries with PACAP (1 nM and 100 nM) for 12 h. The treatment significantly stimulated the subsequent 24 h FSH-induced estradiol production (2.2 and 2.4 fold, respectively). The response seemed to be caused by a stimulation of aromatase activity. Estradiol production induced by testosterone was increased 2.4 and 2.6 fold, respectively, whereas functional FSH-receptors (cAMP production following FSH stimulation) or spontaneous apoptosis (immunohistochemical detection of DNA fragments) was unaffected. We conclude that PACAP priming of immature rat granulosa cells for 12 h increases subsequent FSH induced estradiol production and that PACAP could be involved in the cyclic recruitment of immature follicles in the adult rat ovary.
Expression localisation and functional activity of pituitary adenylate cyclase-activating polypeptide, vasoactive intestinal polypeptide and their receptors in mouse ovary. Barberi M et al. 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.
Follicle stages
Preovulatory, Corpus luteum
Comment
Characterization, expression, and functional activity of pituitary adenylate cyclase-activating polypeptide and its receptors in human granulosa-luteal cells. Morelli MB et al. Context: Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are found in the ovary of mammalian species, though nothing is known about the possible role of PACAP and VIP in the human ovary. Objective: We investigated the expression of PACAP and PACAP/VIP receptors in human granulosa-luteal (GL) cells, obtained from consenting IVF patients attending a private fertility clinic, and assessed a possible antiapoptotic effect of these molecules. Main outcome measures: Expression of PACAP and PACAP/VIP receptor mRNAs in GL cells in response to FSH or LH. Effects of PACAP and VIP on apoptosis, levels of procaspase-3 in GL cells cultured in the absence of serum. Results: After 7 days in culture, GL cells displayed increased responsiveness to FSH and LH (100 ng/ml). FSH and LH promoted PACAP expression, LH in a time-dependent fashion. VIP receptor (VPAC1- and VPAC2-R) mRNAs were also induced by gonadotropin stimulation. Although PACAP receptor (PAC1-R) mRNA was barely detectable, western blot analysis revealed its presence. The apoptotic effect of serum withdrawal from the culture environment was reverted by both PACAP and VIP. Both peptides showed the ability to reverse a decrease in procaspase-3 levels induced by culture in the absence of serum. Conclusions: PACAP and VIP appear to play a role in maintenance of follicle viability as a consequence of the antiapoptotic effect. Further studies are warranted to evaluate the respective roles of PACAP and VIP in ovarian physiology and to identify their mechanism of action.
Effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on progestin biosynthesis in cultured granulosa cells from rat ovary and expression of mRNA encoding PACAP type IA receptor.
Kotani E, et al .
The purpose of this study was to detect the presence of mRNA encoding pituitary adenylate cyclase-activating polypeptide (PACAP) type I receptor in granulosa cells from rat ovary and to examine the effect of PACAP on progestin biosynthesis. mRNA was isolated from granulosa cells from the ovaries of immature rats treated with pregnant mares' serum gonadotrophin. The technique of reverse transcription and polymerase chain reaction with primers specific to PACAP type I receptor were used to demonstrate the expression of mRNA encoding PACAP type IA receptor in these cells. Granulosa cells were also cultured in the absence or presence of 100 ng LH ml-1 with various doses of PACAP-38 (10, 100 and 1000 ng ml-1). At the end of the incubation period, the incubation media were collected and concentrations of progesterone, 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OH-P) and cAMP were measured. Increasing concentrations of PACAP-38 significantly stimulated the production of progestins (progesterone and 20 alpha-OH-P) and cAMP accumulation in a dose-dependent manner (P < 0.01; ANOVA). This effect was observed in media cultured for 24 and 48 h in both basal and LH-stimulated states. PACAP-38 did not significantly affect the ratio of progesterone: 20 alpha-OH-P produced by granulosa cells cultured for 24 h in the LH-stimulated state. However, at 1000 ng ml-1, PACAP-38 significantly decreased the ratio of progesterone to 20 alpha-OH-P production in granulosa cells cultured for 48 h (P < 0.01). These results suggest that granulosa cells from rat ovary express mRNA encoding PACAP type IA receptor and that PACAP may regulate granulosa cell differentiation and play an important role in the reproductive process.