| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Regular Article |
a Department of Molecular and Integrative Physiology, Ralph L. Smith Research Center, University of Kansas Medical Center, Kansas City, Kansas 66160-7338
b The DuPont Pharmaceuticals Co., Wilmington, Delaware 19880-0400
c Department of Medicine (Nephrology) and Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2372
ABSTRACT
Previous observations of ovulation and fertilization defects in cyclooxygenase-2 (COX-2)-deficient mice suggested that COX-2-derived ovarian prostaglandins (PGs) participate in these events. However, the specific PG and its mode of action were unknown. Subsequent studies revealed that mice deficient in EP2, a PGE2-receptor subtype, have reduced litter size, apparently resulting from poor ovulation but more dramatically from impaired fertilization. Using a superovulation regimen and in vitro culture system, we demonstrate herein that the ovulatory process, not follicular growth, oocyte maturation, or fertilization, is primarily affected in adult COX-2- or EP2-deficient mice. Furthermore, our results show that in vitro-matured and -fertilized eggs are capable of subsequent preimplantation development. However, severely compromised ovulation in adult COX-2- or EP2-deficient mice is not manifested in immature (3-wk-old) COX-2- or EP2-deficient mice, suggesting that the process of ovulation is more dependent on PGs in adult mice. Although the processes of implantation and decidualization are defective in COX-2(-/-) mice, our present results demonstrate that these events are normal in EP2-deficient mice, as determined by embryo transfer and experimentally induced decidualization. Collectively, previous and present results suggest that whereas COX-2-derived PGE2 is essential for ovulation via activation of EP2, COX-2-derived prostacyclin is involved in implantation and decidualization via activation of peroxisome proliferator-activated receptor
.
embryo, in vitro fertilization, ovulation, ovum, pregnancy
INTRODUCTION
Prostaglandins (PGs) have long been known to participate in female reproductive functions, including ovulation, fertilization, implantation, and decidualization [1]. These lipid mediators are generated by the cyclooxygenase (COX) pathway. Cyclooxygenase is the rate-limiting enzyme for the conversion of arachidonic acid into PGH2, the precursor for various PGs that are generated via specific PG synthases [2], and it exists in two isoforms, COX-1 and COX-2. These isoforms are encoded by two separate genes and show distinct, cell type-specific expression. The expression of COX-1 is generally constitutive, whereas that of COX-2 is inducible by growth factors, cytokines, and a variety of inflammatory stimuli [2]. Gene-targeting experiments in mice have established distinct functions of these isoforms. For example, COX-1-deficient females are fertile, with specific parturition defects, whereas COX-2-deficient females are infertile, with abnormalities in ovulation, fertilization, implantation, and decidualization [1, 3, 4]. Furthermore, our recent evidence suggests that COX-2-derived prostacyclin (PGI2) is the primary PG at the implantation site, and that this PG participates in implantation via activation of peroxisome proliferator-activated receptor (PPAR)- [5].
The diverse effects of PGs are normally mediated through their G protein-coupled, cell-surface receptors that are linked to different signaling pathways [6], although certain PGs can also function as ligands for PPARs, members of the nuclear hormone superfamily [5]. Cell-surface receptors for PGE2, PGF2
, PGD2, PGI2, and thromboxanes have been cloned as EP, FP, DP, IP, and TP, respectively [7]. Moreover, PGE2 mediates numerous biological functions in the cardiovascular, pulmonary, renal, endocrine, gastrointestinal, neural, reproductive, and immune systems by binding to and activating a set of functionally distinct EP-receptor subtypes: EP1, EP2, EP3, and EP4 [7, 8]. We have previously shown that PGE2-receptor subtypes are uniquely expressed in the peri-implantation mouse uterus [9, 10], suggesting roles of PGE2 in peri-implantation events. However, results of gene-targeting experiments have shown that EP1- and EP3-deficient female mice have normal fertility, suggesting their nonessential roles in ovulation, fertilization, and implantation [11]. In contrast, EP4 deficiency in embryos mostly results in perinatal lethality, preventing further investigations of its role in these events [12]. Interestingly, EP2 null females exhibit impaired reproductive functions, with smaller litter sizes. It has been suggested that defective ovulation and fertilization contribute to this phenotype [13–15]. However, critical investigation is still lacking to define the dysregulation of specific events that contribute to this reduced fertility in EP2 null females. It can be assumed that defective ovulation and fertilization in COX-2-deficient mice result from PGE2 deficiency, whereas the loss of EP2 contributes to these defects in EP2(-/-) mice. Collectively, these data suggest that COX-2-derived PGE2 interacts with its cognate receptor EP2 for directing ovulation and fertilization. However, the site and stage of action of PGE2 during follicular growth, ovulation, or fertilization are not clearly understood.
The success of ovulation is dependent on normal follicular growth, oocyte maturation, and rupture of the preovulatory follicles under the influence of pituitary gonadotropins. Normally, oocytes undergo ovulation after completion of the normal developmental programming within the ovary. Fertilization of mature oocytes occurs if healthy spermatozoa are present within a specific time period at the site of their union in the oviduct ampulla. Therefore, the reduced fertility in COX-2(-/-) or EP2(-/-) female mice could result from either defective follicular growth, oocyte maturation, fertilization, development of preimplantation embryos, and/or implantation. The present investigation examined the roles of PGs during ovulation, fertilization, implantation, and decidualization in mice.
MATERIALS AND METHODS
Reagents
Waymoth MB 752/1 and fetal bovine serum (FBS) were purchased from Gibco/Life Technologies (Grand Island, NY). Mineral oil was purchased from E.R. Squibb & Sons, Inc. (Princeton, NJ). Other reagents were obtained from Sigma Chemical Co. (St. Louis, MO) or Fisher Scientific (Pittsburgh, PA).
Media
Human tubal fluid (HTF) medium was used for in vitro fertilization [16], whereas potassium simplex optimization medium (KSOM) was used for mouse embryo cultures [17]. For in vitro maturation experiments, Waymoth MB 752/1 medium, supplemented with 5% v/v FBS, pyruvic acid (0.23 mM), penicillin G (75 mg/L), streptomycin sulfate (50 mg/L), and human FSH (1 µg/ml; NIDDK/NIH), was used.
Animals and Treatments
The disruption of the COX-2 and EP2 genes has been previously described [3, 13]. Polymerase chain reaction analysis of genomic DNA was used for genotyping. Homozygosity of COX-2 null mice was further confirmed by measuring blood urea nitrogen levels [1]. All of the mice used in the present investigation were housed in the animal care facility at the University of Kansas Medical Center according to National Institutes of Health and institutional guidelines on the care and use of laboratory animals.
Superovulation, In Vitro Fertilization, and Embryo Culture
Mice were subjected to superovulation by i.p. injections of eCG (5 IU), followed by injections of hCG (5 IU) 48 h later. Ovulated eggs were collected from ampullae 14 h after the hCG injections and placed in 100-µl droplets of HTF medium. To disperse cumulus cells, 0.1% hyaluronidase was added to the medium. In our preliminary experiments, a low fertilization rate was observed when ovulated eggs were inseminated in vitro with wild-type spermatozoa from C57Bl/6 mice (13%; 20/153). Therefore, in our subsequent experiments, we performed partial zona-pellucida dissection (PZD) to assist sperm penetration through the zona, as previously described [18]. Spermatozoa were collected from the cauda epididymidis and preincubated for 2–3 h in 400 µl of HTF medium to allow capacitation before insemination. After capacitation, the spermatozoa were introduced into 200-µl droplets of the fertilization medium at a final concentration of 700 spermatozoa/µl. Four hours after insemination, oocytes were washed thoroughly five times, followed by culture in KSOM medium. All embryos were incubated in 100-µl droplets of culture medium overlaid with mineral oil in a humidified atmosphere of 5% CO2 in air at 37°C.
In Vitro Oocyte Maturation
Unexpanded, cumulus cell-enclosed, germinal vesicle-stage oocytes were isolated from mice 47 h after i.p. injections of eCG (5 IU) by puncturing the large antral follicles with a needle. Oocyte-cumulus complexes were matured in 50-µl droplets of maturation medium overlaid with mineral oil for 17 h in a humidified atmosphere of 5% CO2 in air at 37°C. After maturation, oocytes were subjected to fertilization, and the embryos were cultured as described above.
Blastocyst Transfer and Implantation
Pseudopregnancy was induced in EP2(--) virgin female mice by mating with wild-type vasectomized males. Because these mice were suspected to have ovulation defects, they were maintained on daily s.c. injections of progesterone (P4; 1 mg/mouse) from Days 3–7 to ensure that an inadequacy of ovarian P4 excretion was not the cause of implantation failure. Day 4 wild-type blastocysts were transferred into Day 4 pseudopregnant recipient uteri [1, 19]. On Day 8, the number of implantation sites was recorded after i.v. injections of a Chicago blue B dye solution in saline; implantation sites were demarcated as localized blue bands along the uterine horns [19].
Induction of Decidualization
Adult wild-type, EP2(+-), and EP2(--) females were mated with wild-type vasectomized males to induce pseudopregnancy (Day 1 = vaginal plug). The EP2(--) mice were treated daily with P4 (1 mg/mouse) from Days 3–7 to compensate for any deficiency of this steroid because of suspected poor ovulation in these mice. On Day 4, the induction of deciduoma was initiated by an intraluminal infusion of sesame oil (25 µl) in one uterine horn. The contralateral horn served as a control. The mice were killed on Day 8, and wet weights of the infused and noninfused (i.e., control) uterine horns were recorded. The fold induction in uterine wet weights was used as an index to compare decidualization in EP2-deficient mice with that of wild-type and EP2(+-) mice [1].
RESULTS
Ovulation Is Defective in COX-2- or EP2-Deficient Mice
To examine the ovulation status in COX-2 (129xCBl/6)- or EP2 (129SvEvxC57Bl/6)-deficient mice, superovulation was induced by treating 2- to 8-mo-old mice with eCG and hCG. As shown in Figure 1A, an average of 32 eggs was recovered from 20 of 20 wild-type mice. In contrast, an average of approximately four eggs was recovered from 11 of 23 (47.8%) COX-2(--) mice, whereas an average of approximately five eggs was recovered from five of eight (62.5%) EP2(-/-) mice. These results show that the process of ovulation becomes extremely poor with the loss of COX-2 or EP2 functions, suggesting an important role of COX-2-derived PGE2 in this process.
|
Because age could be a determining factor for ovulation and other investigators have observed a minor defect in ovulation for EP2(--) mice, we also compared ovulation in 3-wk-old COX-2(+-) versus COX-2(--) mice and EP2(+-) versus EP2(--) mice using the superovulation protocol as described above. An interesting observation was noted. For example, whereas four of six COX-2(+-) and eight of eight EP2(+-) mice ovulated an average of 38 and 34 eggs, respectively, only 5 of 11 COX-2(--) and 7 of 15 EP2(--) mice ovulated an average of 23 and 17 eggs, respectively (Fig. 1B). However, the number of ovulated eggs between COX-2(+-) and COX-2(--) mice showing ovulation was not statistically different. Nonetheless, ovulation in younger COX-2(--) or EP2(--) mice that responded to gonadotropins for superovulation was superior compared to that in adult COX-2(--) or EP2(--) mice. These results suggest that the ovulatory process in the absence of COX-2 or EP2 is a function of age (i.e., with aging, the ovulatory process becomes more dependent on EP2-mediated PG effects).
Our next objective was to examine whether the fertilization rate and preimplantation embryo development of the ovulated eggs from immature and adult COX-2(--) or EP2(--) mice were normal. We initially observed that only 13% (20/153) of the superovulated wild-type eggs lacking the cumulus layer showed fertilization in vitro after insemination with wild-type spermatozoa obtained from C57Bl/6 mice. This poor fertilization rate was dramatically improved by PZD to assist sperm penetration through the zona [18]. Thus, PZD was routinely used for all subsequent in vitro fertilization experiments. The estimate of fertilization rate was based on two-cell or further embryonic development; thus, the rate presented here underestimates the actual fertilization rate. As shown in Figure 2A, 84% and 63% of the ovulated eggs retrieved from immature COX-2(+-) and EP(+-) mice, respectively, reached at least the two-cell stage after in vitro fertilization, and a majority of them developed to blastocysts. No differences were noted for the in vitro fertilization rate or subsequent development of fertilized eggs retrieved from immature mice with null mutation for the COX-2 or EP2 gene. A similar observation was observed in adult mice, with the exception that the number of ovulated eggs in COX-2(--) or EP2(--) mice was very small (Fig. 2B), although the in vitro fertilization rate and preimplantation development of these eggs after fertilization were similar to those of wild-type mice. However, it should be noted that preimplantation development of fertilized eggs in experiments with EP2 mice were considerably lower than those observed in experiments with COX-2 mice. This lower preimplantation growth rate could result from shuttle changes in culture conditions between the two experiments performed at two different times or from the different genetic backgrounds of the mice used.
|
Ovarian Responses to eCG Are Normal in COX-2- or EP2-Deficient Mice
Although adult COX-2- or EP2-deficient mice have ovulation defects, the site and the underlying cause of these defects were not clearly understood. Ovulation defects might result from defective follicular growth and/or oocyte maturation. To address this issue, we induced follicular growth by treatment with eCG and retrieved oocytes from the eCG-primed preovulatory follicles to examine their in vitro maturational competency. As shown in Figure 3, no significant differences were found in the number of oocyte-cumulus cell complexes retrieved from either COX-2(++) or COX2(--) mice: an average of 18 and 26 oocyte-cumulus complexes were retrieved from five of five COX-2(++) or COX2(--) mice, respectively. Similarly, no differences were found in the number of cumulus-oocyte complexes retrieved from either EP2(++) or EP2(--) mice: an average of 20 and 22 oocyte-cumulus complexes were recovered from five of five EP2(++) and EP2(--) mice, respectively. These results suggest that the ovaries respond normally to eCG for follicular development in the absence of either COX-2 or EP2. We next sought to examine the in vitro maturational competency of these oocytes.
|
Maturational Competency of Oocytes Retrieved from the eCG-Primed Ovaries Is Normal in Adult COX-2- or EP2-Deficient Mice
In vitro culture technique was employed to examine the maturational competency of preovulatory oocyte-cumulus cell complexes. As shown in Figure 4A, 92% (85/92) of COX-2(++) and 88% (90102) of EP2(++) oocytes showed maturation in vitro. This rate was similar to that observed in oocytes obtained from COX-2(--) or EP2(--) mice. The rate of maturation for COX-2(--) oocytes was 92% (119/130), whereas that of EP2(--) oocytes was 80% (86/108). These results suggest that the ovaries of these adult null mice respond to eCG for follicular growth, and that oocyte retrieval and their maturation in vitro are normal. The oocyte maturation process is initiated by expansion of the cumulus mass and germinal vesicle breakdown, followed by final maturation leading to extrusion of the first polar body (Fig. 4B). Our next objective was to examine whether these in vitro-matured oocytes undergo fertilization and normal preimplantation development.
|
Fertilization and Developmental Competence of In Vitro-Matured Oocytes Derived from Adult COX-2- and EP2-Deficient Mice Are Normal
In vitro fertilization followed by embryo culture was employed to determine the competency of in vitro-matured oocytes for fertilization and preimplantation development. The cleavage of fertilized eggs to the two-cell stage or beyond was used as a parameter for successful in vitro fertilization and developmental competency. As shown in Figure 5A, 46% (36/79) of wild-type, in vitro-matured oocytes showed successful fertilization and developed to the two-cell stage or beyond. This rate was similar (51%, 58/113) to that observed for oocytes obtained from COX-2(--) mice. In experiments with EP2 mice, 75% (52/69) of the oocytes obtained from EP2(--) mice successfully fertilized and developed to the two-cell stage or beyond in vitro. This rate was, again, similar (79%, 61/77) to that observed for wild-type oocytes (Fig. 5A). In experiments with COX2(++) or COX-2(--) mice, more than 10% of the in vitro-matured and -fertilized eggs developed to the blastocyst stage, whereas blastocyst formation was more than 30% in experiments with EP2(++) or EP2(--) mice. Furthermore, many of these blastocysts showed signs of zona hatching (Fig. 5B). The differences in the rate of blastocyst formation between the experiments with COX-2 and EP2 mice could result from differences in the genetic backgrounds of the mice used. Nonetheless, the results suggest that COX-2 or EP2 is not essential for oocyte maturation, fertilization, or preimplantation development in vitro.
|
Wild-Type Blastocysts Implant Normally in EP2(--) Mice
Mice deficient in EP2 have reduced fertility with respect to litter size (13–15), and this could result from defects in ovulation, fertilization, implantation, and/or pregnancy maintenance. Although we show herein that EP2-deficient mice exhibit poor ovulation rates, we wanted to determine whether they also exhibit implantation and decidualization defects. Blastocyst transfer experiments were used to address this question. Day 4 wild-type blastocysts were transferred into uteri of Day 4 pseudopregnant wild-type or EP2(--) mice. The implantation rate was 48% (48/100) in EP2-deficient mice (n = 6), and this rate is similar to that observed in wild-type mice (41.7%, 83/199, n = 12). All of the mice in each group showed implantation when examined on Day 8. These results clearly demonstrate that implantation in EP2(--) mice, unlike that in COX-2(--) mice, is normal.
Decidualization Occurs Normally in EP2(--) Mice
Decidualization occurs in the uterine stroma with initiation of the blastocyst attachment to the uterine luminal epithelium. In pregnant mice, the stimulus for decidualization is the implanting blastocyst. However, this process can be experimentally induced in the pseudopregnant mouse uterus by an intraluminal infusion of oil. Using this model, we have previously shown that COX-2 is critical for decidualization in the mouse [1]. However, whether COX-2-derived PGE2, via activation of EP2, plays any major role during this process is not yet known. To address this question, we compared decidualization in EP2(--) mice with that of wild-type or EP2(+-) mice using an established protocol of intraluminal oil infusion [1]. The fold induction in uterine weights between the infused and noninfused horns indicated the extent of decidualization. As shown in Figure 6, EP2(--) mice exhibited an approximately 16-fold increase in wet weight of the infused uterine horns, and this increase was similar to that in wild-type or EP2(+-) mice (15-fold). Because no significant difference in this response was found between the wild-type and EP2(+-) mice, the results were combined and compared with those of the EP2(--) mice. Collectively, these results suggest that both the initial attachment reaction and the subsequent decidualization process are normal in EP2(--) mice.
|
DISCUSSION
The highlights of the present investigation are that ovulation is defective in adult COX-2(--) or EP2(--) mice, although follicular growth in vivo and oocyte maturation in vivo or in vitro are, apparently, normal. Furthermore, subsequent in vitro fertilization of oocytes and their development in vitro proceed normally. The poor ovulation rate in COX-2(--) mice, as recorded in the present investigation, confirms our previous observation [1]. However, the normal follicular development, even in the face of the poor ovulation rate, in these mice is suggestive of normal oocyte maturation. On the other hand, our findings of severe impairment of ovulation in adult EP2(--) mice in response to exogenous gonadotropins are at variance with the modest ovulation defects observed by Hizaki et al.[14] and in sharp contrast to those of Tilly et al. [15], who did not observe reduced ovulation in these mice using a similar superovulation protocol. The major defects these two groups of authors observed were impaired oocyte maturation and fertilization. The differences among the three studies could be caused by the use of different ages of mice and/or their genetic backgrounds. Indeed, our present results also show that the ovulation rate in 3-wk-old COX-2- or EP2-deficient mice was superior to that observed for adult mice. Our results in 3-wk-old EP2(--) mice (129SvEvxC57Bl6 strain) are comparable to those of Hizaki et al. [14], who also used 3-wk-old mice (129/OlaxC57Bl/6 strain) for superovulation. However, the mice used in studies by Tilly et al. [15] were of 129/Olax129SvEv background, although the ages of the mice used in the ovulation and fertilization studies were not indicated. The reason for using 2- to 8-mo-old mice in our studies was based on our initial findings that adult C57Bl6/SJL mice, after superovulation, produced an increased number of superior eggs (data not shown). Recent evidence shows that differential phenotypic responses are evident in gene-targeted mice with different genetic backgrounds, and that physiological responses to a specific stimulus are also dependent on the genetic background of the mice [20, 21]. Our present results suggest that the ovulation efficiency in wild-type mice is not significantly altered between immature and adult mice, but that in the absence of COX-2 or EP2, this process becomes defective with aging. The mechanism underlying this observation is currently unknown.
The release of the ovum from the follicle requires both activation and expansion of the cumulus oophorum and initiation of proteolytic cascades to lyse the follicular wall [22]. Activation of the cumulus oophorum is characterized by polarization and expansion of the granulosa cells surrounding the oocyte, with the production of hyaluronic acid-enriched proteoglycans [23, 24]. This process is critical to successful ovulation and fertilization, because inhibition of hyaluronic acid synthesis suppresses cumulus cells expansion and decreases fertilization rates [25]. Defective ovulation in COX-2-deficient mice was attributed to an abnormal cumulus oophorum expansion and subsequent stigmata formation [26]. Cyclooxygenase-2 is induced in granulosa cells in response to the preovulatory gonadotropin surge [27–29], and the coordinate expression of COX-2 in granulosa cells of the mature follicles with the gonadotropin surge provides compelling evidence that COX-2-derived PGs are important for ovulation [29–33]. An accumulation of COX-2 is also observed in the cumulus cells surrounding oocytes in the antral follicles and in the ovulated eggs of wild-type mice [1], suggesting its role in cumulus expansion and oocyte maturation in vivo before ovulation.
Treatment with gonadotropins induces EP2 expression in a temporal fashion, similar to that of COX-2, in cumulus cells [14]. These results suggest that COX-2-derived PGE2 signals, via one of its cognate receptor subtypes, EP2 in the processes of cumulus expansion and ovulation. In EP2-deficient mice, cumulus expansion proceeded normally in preovulatory follicles but became abortive in a number of ovulated complexes, indicating that EP2 is involved with cumulus expansion in the oviduct in vivo [14]. These results demonstrate the importance of EP2-induced cumulus expansion during the final stage of oocyte maturation [14]. In contrast, our studies provide evidence that cumulus-oocyte complexes retrieved from EP2-deficient mice after eCG priming show normal cumulus expansion and oocyte maturation in the presence of FSH in vitro. This suggests that EP2 is not essential for these processes, at least under in vitro conditions. Furthermore, the poor fertilization rate in EP2(--) mice, as observed by other investigators, could result from zona hardening and/or other associated defects in vivo that normally occur under in vitro conditions [34]. This assumption is consistent with our observation of heightened in vitro fertilization rates of wild-type, COX2(--) or EP2(--) oocytes after zona nicking. In addition, asynchronous ovulation, or defective sperm migration and/or capacitation, in the reproductive tract of EP2-deficient females could also be responsible for poor fertilization in vivo.
The successful fertilization and preimplantation development of in vitro-matured and -fertilized COX-2(--) or EP2(--) oocytes suggest that COX-2-derived PGE2 of maternal origin is not required for these processes. Because wild-type spermatozoa were used for insemination generating all heterozygous embryos, PGs of paternal origin may have influenced fertilization, whereas PGs of paternal and/or embryonic (after activation of the embryonic genome) origin may have influenced subsequent development. Because both COX-2- and EP2-deficient males are fertile, PGs of sperm origin likely contribute little to fertilization.
Although the ovulation process is severely affected in adult COX-2- or EP2-deficient mice, the mechanism by which COX-2-derived PGE2 affects this process is not clearly understood. Proteolytic cascades are involved in the process of ovulation; however, the exact nature of the proteolytic events is not yet clearly defined. It is known, however, that P4 is involved in ovulation, because inhibition of P4 synthesis blocks this process [35] and oocyte release is absent in P4 receptor-deficient mice [36]. A recent report provides evidence that proteases of the disintegrin-metalloproteinase family (ADAMTS-1) and cathepsin L, but not metalloproteinases, are involved in P4-regulated ovulation in the mouse [37]. Determining whether ovulation defects in COX-2- or EP2-deficient mice involve ADAMTS-1 or cathepsin L will require further investigation. However, a recent finding of heightened synthesis of P4, PGs, and EP2 in mouse granulosa cells by oocyte-derived growth differentiation factor-9 (GDF-9) suggests a relationship between P4 and PGs in the ovulatory process, and that COX-2-derived PGE2 and its receptor subtype EP2 are the downstream targets of GDF-9 [38].
Although implantation and decidualization are defective in COX-2-deficient mice [1, 5], our present results and those of Hizaki et al. [14] demonstrate that these events are apparently normal in EP2-deficient mice. In conclusion, our previous and present investigations provide evidence that whereas ovarian COX-2-derived PGE2 is important for ovulation, the uterine COX-2-derived PGI2 is important for implantation, demonstrating diversification of COX-2-derived PGs in female reproduction.
FOOTNOTES
First decision: 5 December 2000.
1 Supported in part by a grant from the Mellon Foundation, NICHD grants HD 12304 and HD 29968, as part of the National Cooperative Program on Markers of Uterine Receptivity for Blastocyst Implantation (S.K.D.), and NIGMS grant GM 15431 (R.M.B.). S.K.D. is an NICHD (NIH) MERIT Awardee. H.M. is a KUMC Biomedical postdoctoral fellow. Center grants in Reproductive Biology (HD 33994) and Mental Retardation (HD 02528) from the NIH provided access to various core facilities. 
2 Correspondence: Sudhansu K. Dey, Department of Molecular and Integrative Physiology, MRRC 37/3017, University of Kansas Medical Center, Kansas City, KS 66160-7338. FAX: 913 588 5677; sdey{at}kumc.edu
Accepted: January 8, 2001.
Received: October 24, 2000.
REFERENCES
. Genes Dev 1999; 13:1561–1574This article has been cited by other articles:
|
|
 |
|
  X. Sun, H. Wang, M. Okabe, K. Mackie, P. J. Kingsley, L. J. Marnett, B. F. Cravatt, and S. K. Dey Genetic Loss of Faah Compromises Male Fertility in Mice Biol Reprod, February 1, 2009; 80(2): 235 - 242. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Kurusu, M. Jinno, H. Ehara, T. Yonezawa, and M. Kawaminami Inhibition of ovulation by a lipoxygenase inhibitor involves reduced cyclooxygenase-2 expression and prostaglandin E2 production in gonadotropin-primed immature rats Reproduction, January 1, 2009; 137(1): 59 - 66. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Sayasith, N. Bouchard, M. Dore, and J. Sirois Regulation of Bovine Tumor Necrosis Factor-{alpha}-Induced Protein 6 in Ovarian Follicles during the Ovulatory Process and Promoter Activation in Granulosa Cells Endocrinology, December 1, 2008; 149(12): 6213 - 6225. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Eo, K. Han, K. M Murphy, H. Song, and H. J. Lim Etv5, an ETS transcription factor, is expressed in granulosa and cumulus cells and serves as a transcriptional regulator of the cyclooxygenase-2 J. Endocrinol., August 1, 2008; 198(2): 281 - 290. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Shimada, Y. Yanai, T. Okazaki, N. Noma, I. Kawashima, T. Mori, and J. S. Richards Hyaluronan fragments generated by sperm-secreted hyaluronidase stimulate cytokine/chemokine production via the TLR2 and TLR4 pathway in cumulus cells of ovulated COCs, which may enhance fertilization Development, June 1, 2008; 135(11): 2001 - 2011. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Dragovic, L. J. Ritter, S. J. Schulz, F. Amato, J. G. Thompson, D. T. Armstrong, and R. B. Gilchrist Oocyte-Secreted Factor Activation of SMAD 2/3 Signaling Enables Initiation of Mouse Cumulus Cell Expansion Biol Reprod, May 1, 2007; 76(5): 848 - 857. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Hong, S. T. Kim, S. Tranguch, D. F Smith, and S. K Dey Deficiency of co-chaperone immunophilin FKBP52 compromises sperm fertilizing capacity Reproduction, February 1, 2007; 133(2): 395 - 403. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Sayasith, M. Dore, and J. Sirois Molecular characterization of tumor necrosis {alpha}-induced protein 6 and its human chorionic gonadotropin-dependent induction in theca and mural granulosa cells of equine preovulatory follicles Reproduction, January 1, 2007; 133(1): 135 - 145. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Takahashi, J. D. Morrow, H. Wang, and S. K. Dey Cyclooxygenase-2-derived Prostaglandin E2 Directs Oocyte Maturation by Differentially Influencing Multiple Signaling Pathways J. Biol. Chem., December 1, 2006; 281(48): 37117 - 37129. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K.R. Barnett, C. Schilling, C.R. Greenfeld, D. Tomic, and J.A. Flaws Ovarian follicle development and transgenic mouse models Hum. Reprod. Update, September 1, 2006; 12(5): 537 - 555. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. L. Lopes, J. Desmarais, S. Ledoux, N. Y. Gevry, P. Lefevre, and B. D. Murphy Transcriptional Regulation of Uterine Vascular Endothelial Growth Factor during Early Gestation in a Carnivore Model, Mustela vison J. Biol. Chem., August 25, 2006; 281(34): 24602 - 24611. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Wang, S. K. Dey, and M. Maccarrone Jekyll and Hyde: Two Faces of Cannabinoid Signaling in Male and Female Fertility Endocr. Rev., August 1, 2006; 27(5): 427 - 448. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. S. Bata, M. Al-Ramahi, A. S. Salhab, M. N. Gharaibeh, and J. Schwartz Delay of Ovulation by Meloxicam in Healthy Cycling Volunteers: A Placebo-Controlled, Double-blind, Crossover Study. J. Clin. Pharmacol., August 1, 2006; 46(8): 925 - 932. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Shimada, I. Hernandez-Gonzalez, I. Gonzalez-Robayna, and J. S. Richards Paracrine and Autocrine Regulation of Epidermal Growth Factor-Like Factors in Cumulus Oocyte Complexes and Granulosa Cells: Key Roles for Prostaglandin Synthase 2 and Progesterone Receptor Mol. Endocrinol., June 1, 2006; 20(6): 1352 - 1365. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D.X. Lin, Z.M. Lei, and Ch.V. Rao Dependence of Uterine Cyclooxygenase2 Expression on Luteinizing Hormone Signaling Biol Reprod, August 1, 2005; 73(2): 256 - 260. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W. Newman, J. E. Stok, J. D. Vidal, C. J. Corbin, Q. Huang, B. D. Hammock, and A. J. Conley Cytochrome P450-Dependent Lipid Metabolism in Preovulatory Follicles Endocrinology, November 1, 2004; 145(11): 5097 - 5105. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Guzeloglu, T. R. Bilby, A. Meikle, S. Kamimura, A. Kowalski, F. Michel, L. A. MacLaren, and W. W. Thatcher Pregnancy and Bovine Somatotropin in Nonlactating Dairy Cows: II. Endometrial Gene Expression Related to Maintenance of Pregnancy J Dairy Sci, October 1, 2004; 87(10): 3268 - 3279. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Sirois, K. Sayasith, K. A. Brown, A. E. Stock, N. Bouchard, and M. Dore Cyclooxygenase-2 and its role in ovulation: a 2004 account Hum. Reprod. Update, September 1, 2004; 10(5): 373 - 385. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Guzeloglu, F. Michel, and W. W. Thatcher Differential Effects of Interferon-{tau} on the Prostaglandin Synthetic Pathway in Bovine Endometrial Cells Treated with Phorbol Ester J Dairy Sci, July 1, 2004; 87(7): 2032 - 2041. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Guzeloglu, P. Subramaniam, F. Michel, and W. W. Thatcher Interferon-{tau} Induces Degradation of Prostaglandin H Synthase-2 Messenger RNA in Bovine Endometrial Cells Through a Transcription-Dependent Mechanism Biol Reprod, July 1, 2004; 71(1): 170 - 176. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Wang, W.-g. Ma, L. Tejada, H. Zhang, J. D. Morrow, S. K. Das, and S. K. Dey Rescue of Female Infertility from the Loss of Cyclooxygenase-2 by Compensatory Up-regulation of Cyclooxygenase-1 Is a Function of Genetic Makeup J. Biol. Chem., March 12, 2004; 279(11): 10649 - 10658. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Emond, L. A. MacLaren, S. Kimmins, J. A. Arosh, M. A. Fortier, and R. D. Lambert Expression of Cyclooxygenase-2 and Granulocyte-Macrophage Colony-Stimulating Factor in the Endometrial Epithelium of the Cow Is Up-Regulated During Early Pregnancy and in Response to Intrauterine Infusions of Interferon-{tau} Biol Reprod, January 1, 2004; 70(1): 54 - 64. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. L. Russell, K. M. H. Doyle, S. A. Ochsner, J. D. Sandy, and J. S. Richards Processing and Localization of ADAMTS-1 and Proteolytic Cleavage of Versican during Cumulus Matrix Expansion and Ovulation J. Biol. Chem., October 24, 2003; 278(43): 42330 - 42339. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Ochsner, A. J. Day, M. S. Rugg, R. M. Breyer, R. H. Gomer, and J. S. Richards Disrupted Function of Tumor Necrosis Factor-{alpha}-Stimulated Gene 6 Blocks Cumulus Cell-Oocyte Complex Expansion Endocrinology, October 1, 2003; 144(10): 4376 - 4384. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Song, H. Lim, B. C. Paria, H. Matsumoto, L. L. Swift, J. Morrow, J. V. Bonventre, and S. K. Dey Cytosolic phospholipase A2{alpha} is crucial for 'on-time' embryo implantation that directs subsequent development Development, March 8, 2003; 129(12): 2879 - 2889. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Ochsner, D. L. Russell, A. J. Day, R. M. Breyer, and J. S. Richards Decreased Expression of Tumor Necrosis Factor-{alpha}-Stimulated Gene 6 in Cumulus Cells of the Cyclooxygenase-2 and EP2 Null Mice Endocrinology, March 1, 2003; 144(3): 1008 - 1019. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Segi, K. Haraguchi, Y. Sugimoto, M. Tsuji, H. Tsunekawa, S. Tamba, K. Tsuboi, S. Tanaka, and A. Ichikawa Expression of Messenger RNA for Prostaglandin E Receptor Subtypes EP4/EP2 and Cyclooxygenase Isozymes in Mouse Periovulatory Follicles and Oviducts During Superovulation Biol Reprod, March 1, 2003; 68(3): 804 - 811. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Patino, G. Yoshizaki, D. Bolamba, and P. Thomas Role of Arachidonic Acid and Protein Kinase C During Maturation-Inducing Hormone-Dependent Meiotic Resumption and Ovulation in Ovarian Follicles of Atlantic Croaker Biol Reprod, February 1, 2003; 68(2): 516 - 523. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Gaytan, E. Tarradas, C. Bellido, C. Morales, and J. E. Sanchez-Criado Prostaglandin E1 Inhibits Abnormal Follicle Rupture and Restores Ovulation in Indomethacin-Treated Rats Biol Reprod, October 1, 2002; 67(4): 1140 - 1147. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Matsumoto, W.-g. Ma, T. Daikoku, X. Zhao, B. C. Paria, S. K. Das, J. M. Trzaskos, and S. K. Dey Cyclooxygenase-2 Differentially Directs Uterine Angiogenesis during Implantation in Mice J. Biol. Chem., August 2, 2002; 277(32): 29260 - 29267. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-L. Wu and M. C. Wiltbank Transcriptional Regulation of the Cyclooxygenase-2 Gene Changes from Protein Kinase (PK) A- to PKC-Dependence after Luteinization of Granulosa Cells Biol Reprod, May 1, 2002; 66(5): 1505 - 1514. [Abstract] [Full Text]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
2 test and were not significantly different between homozygous null and wild-type/heterozygous mice. The number of embryos that developed to beyond the two-cell stage or blastocysts/total number of fertilized eggs is shown above each bar
