NCBI Summary:
Prostaglandin-endoperoxide synthase (PTGS), also known as cyclooxygenase, is the key enzyme in prostaglandin biosynthesis, and acts both as a dioxygenase and as a peroxidase. There are two isozymes of PTGS: a constitutive PTGS1 and an inducible PTGS2, which differ in their regulation of expression and tissue distribution. This gene encodes PTGS1, which regulates angiogenesis in endothelial cells, and is inhibited by nonsteroidal anti-inflammatory drugs such as aspirin. PTGS1 is thought to be involved in cell-cell signaling and maintaining tissue homeostasis. Alternative splicing of this gene generates two transcript variants. The expression of these two transcripts is differentially regulated by relevant cytokines and growth factors.
General function
Enzyme
Comment
Cellular localization
Cytoplasmic
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Ovarian function
Follicle development
Comment
Cyclooxygenase-1 Inhibition Prolongs Postnatal Ovarian Follicle Lifespan in Mice. Smith ER 2013 et al.
Menopause is the permanent cessation of menstruation that results from depletion of ovarian germ cells and follicles. Although most animals experience reproductive senescence, the mechanisms differ from that in women, who may live more than one-third of their lives after menopause and consequently face the risk of a number of menopause-associated health problems. Understanding factors that influence ovarian aging may provide strategies to delay or alleviate physiological alterations that take place in post-menopausal women. The germ cell-deficient Wv mice recapitulate follicle loss and long post-reproductive lifespan, and model many physiological changes that take place in post-menopausal women. Here, using genetic and pharmacological approaches, we found that inhibition of cyclooxygenase-1 but not cyclooxygenase-2 in Wv mice delays germ cell depletion and preserves ovarian follicles. Cyclooxygenase-1 inhibition slows down follicle maturation at the conversion of primary to secondary follicles and prolongs postnatal ovarian follicle lifespan. The current study suggests that inhibition of cyclooxygenase-1 may be able to delay ovarian aging and modulate menopausal timing.
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Expression regulated by
Comment
Ovarian localization
Luteal cells
Comment
The corpus luteum (CL) is a transient ovarian endocrine gland formed from the ovulated follicle. Progesterone (P4) is the primary secretory product of CL and essential for establishment of pregnancy in mammals. In the cyclic female, the life span of CL is characterized by luteal development, maintenance and regression regulated by complex interactions between luteotrophic and luteolytic mediators. It is universally accepted that PGF2a is the luteolysin while PGE2 is considered as a luteotropin in most mammals irrespective of origin either uterus and /or CL. New emerging concepts emphasize the autocrine and paracrine actions of luteal PGs in CL function. However, there is no report on selective biosynthesis and cellular transport of luteal PGE2 and PGF2alpha in the CL of any species. Arosh J et al 2004 have studied the expression of enzymes involved in the metabolism of PGE2 and PGF2alpha, cyclooxygenase (COX) 1 and 2, PG synthases (PGES and PGFS), prostaglandin 15-dehydrogenase (PGDH), and PG transporter (PGT) as well as receptors (EP2, EP3 and FP) throughout the CL life span using a bovine model. COX-1, PGFS and PGDH are expressed at constant levels whereas COX-2, PGES, PGT, EP2, EP3 and FP are highly modulated during different phases of the CL life span. The PG components are preferentially expressed in large luteal cells. The results indicate that PGE2 biosynthesis, transport and signaling cascades are selectively activated during luteal maintenance. By contrast PGF2alpha system is activated during luteal regression.