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General Comment |
NCBI Summary:
This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. However, this protein is considered a member of the cytochrome P450 superfamily on the basis of sequence similarity rather than functional similarity. This endoplasmic reticulum membrane protein catalyzes the conversion of prostglandin H2 to prostacyclin (prostaglandin I2), a potent vasodilator and inhibitor of platelet aggregation. An imbalance of prostacyclin and its physiological antagonist thromboxane A2 contribute to the development of myocardial infarction, stroke, and atherosclerosis. [provided by RefSeq, Jul 2008]
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Comment |
Prostacyclin synthesis and prostacyclin receptor expression in the porcine corpus luteum: evidence for a luteotropic role in vitro. Szymanska M et al. (2018) The prostacyclin (prostaglandin I2) signaling system is an essential regulator of vascular homeostasis. Since the corpus luteum is a highly vascularized gland, prostacyclin seems to be crucial for luteal development and function. Although progress has been made in understanding the luteotropic action of prostacyclin in mammals, its role in the porcine corpus luteum remains to be determined. Therefore, studies were conducted to (1) determine profiles of prostacyclin synthase expression and prostacyclin metabolite concentration, as well as prostacyclin G-protein-coupled receptor expression in porcine luteal tissue on days 2 to 16 of the estrous cycle and days 10 to 30 of pregnancy using real-time PCR, western blot, or enzyme immunoassay; and (2) examine the effect of prostacyclin on progesterone synthesis in vitro. To accomplish the second aim, luteal cells were treated with prostacyclin analogs, iloprost and carbaprostacyclin, in the presence or absence of prostacyclin receptor antagonists. The mRNA expression of cytochrome P450 family 11 subfamily A member 1 and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 was analyzed using real-time PCR, while progesterone concentration in culture medium was assessed by radioimmunoassay.Dynamic changes of prostacyclin synthase and prostacyclin receptor expression were observed in porcine luteal tissue during the estrous cycle and early pregnancy. Moreover, prostacyclin stimulated progesterone production and this effect was abolished by the addition of prostacyclin receptor antagonists. Our findings provide strong evidence that prostacyclin and its signaling system are present in corpus luteum of the pig and may directly promote luteotropic activity through upregulation of progesterone synthesis.//////////////////
Iloprost, a prostacyclin analogue, stimulates meiotic maturation and early embryonic development in pigs. Kim JS et al. Oviduct fluid contains various cytokines and growth factors that enhance the embryo development during the preimplantation period. In hatched embryos, prostacyclin (PGI(2)) improves implantation, but its role during oocyte maturation and early embryo development remains contentious. Therefore, in the present study, we examined the effects of a PGI(2) analogue (iloprost) on meiotic maturation and early embryonic development in pigs, as well on the structural integrity, mitochondrial membrane potential and apoptosis in blastocysts. First, meiotic maturation in pig oocytes was examined in the presence of increasing concentrations of iloprost (1, 5 and 10 muM). After IVM, a higher proportion of iloprost-treated compared with untreated oocytes was in MII (90.0% v. 65.7%, respectively; P < 0.05). In addition, protein kinase A activity increased in iloprost-treated oocytes, indicating increased intracellular cAMP concentrations. After 22 h iloprost treatment (44 h total incubation time), western blotting demonstrated increased expression of extracellular signal-regulated kinase (ERK) 1/2, phosphorylated (p-) ERK1/2, cAMP response element-binding protein (CREB), p-CREB and cyclo-oxygenase-2, indicating activation of the mitogen-activated protein kinase and PGI(2) pathways. In addition, the frequency of polyspermy decreased in iloprost-treated oocytes (19.9%) compared with control (35.8%), whereas the rate of blastocyst formation increased (P < 0.05). Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) showed that the number of nuclei containing fragmented DNA at the blastocyst stage decreased in the iloprost-treated group compared with control (1.2% v. 3.6%, respectively). In conclusion, iloprost appears to play a direct role in porcine oocyte maturation by enhancing blastocyst structure and survival.
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