New evidence for the involvement of prostaglandin receptor EP4b in ovulation of the medaka, Oryzias latipes

Fujimori, Chika; Ogiwara, Katsueki; Hagiwara, Akane; Takahashi, Takayuki

doi:10.1016/j.mce.2012.05.013

Cited by 42 publications

(25 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, the present study showed one of the PGs receptors, Ptger4, was markedly up-regulated prior to ovulation in both mouse and zebrafish data sets. It has already been shown that Pgr directly regulates ptger4 in the preovulatory follicles of medaka (Fujimori et al, 2012; Hagiwara et al, 2014). In contrast, the role of PTGER4 in ovulation has been overlooked in mammals as studies have focused more on the role of PTGER2 in COC expansion and ovulation (Harris et al, 2011; Kim SO et al, 2014; Trau et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

Transcriptomic signatures for ovulation in vertebrates

Liu

Brewer

Chen

et al. 2017

General and Comparative Endocrinology

View full text Add to dashboard Cite

The central roles of luteinizing hormone (LH), progestin and their receptors for initiating ovulation have been well established. However, signaling pathways and downstream targets such as proteases that are essential for the rupture of follicular cells are still unclear. Recently, we found anovulation in nuclear progestin receptor (Pgr) knockout (Pgr-KO) zebrafish, which offers a new model for examining genes and pathways that are important for ovulation and fertility. In this study, we examined expression of all transcripts using RNA-Seq in preovulatory follicular cells collected following the final oocyte maturation, but prior to ovulation, from wild-type (WT) or Pgr-KO fish. Differential expression analysis revealed 3,567 genes significantly differentially expressed between WT and Pgr-KO fish (fold change ≥2, p<0.05). Among those, 1,543 gene transcripts were significantly more expressed, while 2,024 genes were significantly less expressed, in WT than those in Pgr-KO. We then retrieved and compared transcriptional data from online databases and further identified 661 conserved genes in fish, mice, and humans that showed similar levels of high (283 genes) or low (387) expression in animals that were ovulating compared to those with no ovulation. For the first time, ovulatory genes and their involved biological processes and pathways were also visualized using Enrichment Map and Cytoscape. Intriguingly, enrichment analysis indicated that the genes with higher expression were involved in multiple ovulatory pathways and processes such as inflammatory response, angiogenesis, cytokine production, cell migration, chemotaxis, MAPK, focal adhesion, and cytoskeleton reorganization. In contrast, the genes with lower expression were mainly involved in DNA replication, DNA repair, DNA methylation, RNA processing, telomere maintenance, spindle assembling, nuclear acid transport, catabolic processes, and nuclear and cell division. Our results indicate that a large set of genes (>3,000) is differentially regulated in the follicular cells in zebrafish prior to ovulation, terminating programs such as growth and proliferation, and beginning processes including the inflammatory response and apoptosis. Further studies are required to establish relationships among these genes and an ovulatory circuit in the zebrafish model.

show abstract

Section: Discussionmentioning

confidence: 99%

Transcriptomic signatures for ovulation in vertebrates

Liu

Brewer

Chen

et al. 2017

General and Comparative Endocrinology

View full text Add to dashboard Cite

show abstract

“…Real-time PCR was performed using an Applied Biosystems 7300 Real-Time PCR System (Life technologies Inc., Rockville, MD). The PCR mixture preparation, PCR, and data analysis were carried out according to the previously reported protocol [68], [74]. To normalize the transcript levels of gonadotropin subunits (pituitary), gonadotropin receptors, metalloproteinases and their inhibitor (ovarian follicles), we tested the housekeeping genes cytoplasmic actin ( actb ), 18S rRNA ( rn18s1 ) and ribosomal protein L7 ( rpl7 ).…”

Section: Methodsmentioning

confidence: 99%

Characterization of Luteinizing Hormone and Luteinizing Hormone Receptor and Their Indispensable Role in the Ovulatory Process of the Medaka

et al. 2013

Self Cite

View full text Add to dashboard Cite

The molecular properties and roles of luteinizing hormone (Lh) and its receptor (Lhcgrbb) have not been studied for the medaka (Oryzias latipes), which is an excellent animal model for ovulation studies. Here, we characterized the medaka Lh/Lhcgrbb system, with attention to its involvement in the ovulatory process of this teleost fish. In the medaka ovary, follicle-stimulating hormone receptor mRNA was expressed in small and medium-sized follicles, while lhcgrbb mRNA was expressed in the follicle layers of all growing follicles. Experiments using HEK 293T cells expressing medaka Lhcgrbb in vitro revealed that gonadotropin from pregnant mare’s serum and medaka recombinant Lh (rLh) bound to the fish Lhcgrbb. The fish gonadotropin subunits Gtha, Fshb, and Lhb were essentially expressed at fairly constant levels in the pituitary of the fish during a 24-h spawning cycle. Using medaka rLh, we developed a follicle culture system that allowed us to follow the whole process of oocyte maturation and ovulation in vitro. This follicle culture method enabled us to determine that the Lh surge for the preovulatory follicle occurred in vivo between 19 and 15 h before ovulation. The present study also showed that oocyte maturation and ovulation were delayed several hours in vitro compared with in vivo. Treatment of large follicles with medaka rLh in vitro significantly increased the expression of Mmp15, which was previously demonstrated to be crucial for ovulation in the fish. These findings demonstrate that Lh/Lhcgrbb is critically involved in the induction of oocyte maturation and ovulation.

show abstract

“…In this study, the expression of many proteins which associated with oxidative stress was changed in the germ cells after treatments with Bap and DBP and may associate with their reproductive toxicology. PKA C-beta and tubulin beta-5, which would be associated with germ cell structure, meiosis process and male fertility (Burton et al, 2006;Fujimori et al, 2012), were up-regulated after treatment with Bap. HnRNP DL, which acted as a transcriptional regulator and was associated with cell cycle (Akagi et al, 2000), also varied when exposed to Bap.…”

Section: The Changes In Total Protein Expressionmentioning

confidence: 98%

Combined Effects of Dibutyl Phthalate (DBP) and Benzo(a)Pyrene on Fertility in Male Rats

Huang¹,

Chen²,

Shu

2014

GEP

View full text Add to dashboard Cite

Our previous studies revealed the polycyclic aromatic hydrocarbon and phthalic acid esters were the major organic pollutants in the Jialing River and Yangtze River in the Three Gorges area, and they might cause the toxicity in male fertility when combined. Thus we used di-n-butyl phthalate (DBP) and Benzo(a)pyrene (Bap) as their representatives respectively to explore their effects on the spermatogenesis in male rats. Male Sprague Dawley rats were randomly divided into 4 groups and respectively exposed to corn oil, Bap (5 mg/kg/d), DBP (250 mg/kg/d), and combined doses of Bap (5 mg/kg/d) and DBP (250 mg/kg/d) for 90 days. We observed a significant increase in the stillbirth rate after Bap and combined treatments, while the mean area of seminiferous tubules was reduced after Bap, DBP and combined treatments. Bap and combined treatment had a suppressing effect on meiosis in germ cells, which reduced the haploid contents and the ratio between haploid and diploid but increased the tetraploid and diploid contents and the ratio between haploid and tetraploid. These effects were more obvious in the combined group. Furthermore, the expression of a number of proteins was changed, of which was associated with the oxidative stress and cAMP/PKA signaling pathway. Our results suggest that Bap has significant toxic effects on male fertility, while the combined treatment of Bap and DBP has more toxic effects.

show abstract

New evidence for the involvement of prostaglandin receptor EP4b in ovulation of the medaka, Oryzias latipes

Cited by 42 publications

References 47 publications

Transcriptomic signatures for ovulation in vertebrates

Transcriptomic signatures for ovulation in vertebrates

Characterization of Luteinizing Hormone and Luteinizing Hormone Receptor and Their Indispensable Role in the Ovulatory Process of the Medaka

Combined Effects of Dibutyl Phthalate (DBP) and Benzo(a)Pyrene on Fertility in Male Rats

Contact Info

Product

Resources

About