Role of Cyclic Nucleotide Phosphodiesterases During Meiotic Resumption From Diplotene Arrest in Mammalian Oocytes. Issue 3 (30th September 2016)

• Record Type: Journal Article
• Authors: Gupta, Anumegha; Tiwari, Meenakshi; Prasad, Shilpa; Chaube, Shail K.
• Is Part Of: Journal of cellular biochemistry. Volume 118:Issue 3(2017)
• Page Start: 446
• Page End: 452
• Publication Date: 2016-09-30
• Subjects: PDEs -- CYCLIC NUCLEOTIDES -- MPF -- MEIOTIC CELL CYCLE -- MAMMALIAN OOCYTES; Cytochemistry -- Periodicals; 572
• DOI: 10.1002/jcb.25748
• Languages: English
• ISSNs: 0730-2312

Abstract

ABSTRACT: Cyclic nucleotide phosphodiesterases (PDEs) are group of enzymes that hydrolyze cyclic nucleotides in wide variety of cell types including encircling granulosa cells as well as associated oocytes. One group of PDEs are located in encircling granulosa cells and another group get expressed in the oocyte, while few other PDEs are expressed in both compartments. The PDE1A, PDE4D, PDE5A, PDE8A, and PDE8B are granulosa cell specific PDEs that hydrolyze adenosine 3′, 5′‐cyclic monophosphate (cAMP) as well as guanosine 3′, 5′‐cyclic monophosphate (cGMP) with different affinities. PDE3A, PDE8A as well as PDE9A are expressed in oocyte and specifically responsible for the cyclic nucleotide hydrolysis in the oocyte itself. Few other PDEs such as PDE7B, PDE10A, and PDE11A are either detected in granulosa cells or oocytes. Activation of these PDEs either in encircling granulosa cells or in oocyte directly or indirectly reduces intraoocyte cAMP level. Reduction of intraoocyte cAMP level modulates phosphorylation status of cyclin‐dependent kinase 1 (Cdk1) and triggers cyclin B1 degradation that destabilizes maturation promoting factor (MPF) and/or increases Cdk1 activity. The destabilized MPF and/or increased Cdk1 activity leads to resumption of meiosis, which initiates the achievement of meiotic competency in preovulatory follicles of several mammalian species. Use of specific PDEs inhibitors block cyclic nucleotides hydrolysis that results in increase of intraoocyte cyclic nucleotides level, which leads to maintenance of meiotic arrest at diplotene stage in vivo as well as in vitro. Thus, cyclic nucleotide PDEs play important role in the achievement of meiotic competency by reducing intraoocyte cyclic nucleotides level in mammalian oocytes. J. Cell. Biochem. 118: 446–452, 2017. © 2016 Wiley Periodicals, Inc. Abstract : The PDEs isoforms are highly compartmentalized in encircling granulosa cells as well as oocyte in preovulatory follicles of mammalian ovary. These PDE isoforms either present in granulosa cells, oocyte or both directly/indirectly alter cAMP as well as cGMP levels to affect downstream pathway during meiotic resumption from diplotene arrest to M‐II arrest, a period in which oocyte achieves meiotic competency. The decreased levels of cAMP as well as cGMP alter specific phosphorylation status of Cdk1 and triggers dissociation thereby degradation of cyclin B1. As a result, MPF is destabilized that finally induces achievement of meiotic competency in follicular oocyte just prior to ovulation.