Transcriptomic analysis of cyclic AMP response in bovine cumulus cells

Abstract

Khan DR, Guillemette C, Sirard MA, Richard FJ. Transcriptomic analysis of cyclic AMP response in bovine cumulus cells. Physiol Genomics 47: 432-442, 2015. First published June 16, 2015 doi:10.1152/physiolgenomics.00043.2015.-Acquisition of oocyte developmental competence needs to be understood to improve clinical outcomes of assisted reproduction. The stimulation of cumulus cell concentration of cyclic adenosine 3=5=-monophosphate (cAMP) by pharmacological agents during in vitro maturation (IVM) participates in improvement of oocyte quality. However, precise coordination and downstream targets of cAMP signaling in cumulus cells are largely unknown. We have previously demonstrated better embryo development after cAMP stimulation for first 6 h during IVM. Using this model, we investigated cAMP signaling in cumulus cells through in vitro culture of cumulus-oocyte complexes (COCs) in the presence of cAMP raising agents: forskolin, IBMX, and dipyridamole (here called FID treatment). Transcriptomic analysis of cumulus cells indicated that FID-induced differentially expressed transcripts were implicated in cumulus expansion, steroidogenesis, cell metabolism, and oocyte competence. Functional genomic analysis revealed that protein kinase-A (PKA), extracellular signal regulated kinases (ERK1/2), and calcium (Ca 2ϩ ) pathways as key regulators of FID signaling. Inhibition of PKA (H89) in FID-supplemented COCs or substitution of FID with calcium ionophore (A23187) demonstrated that FID activated primarily the PKA pathway which inhibited ERK1/2 phosphorylation and was upstream of calcium signaling. Furthermore, inhibition of ERK1/2 phosphorylation by FID supported a regulation by dual specific phosphatase (DUSP1) via PKA. Our findings imply that cAMP (FID) regulates cell metabolism, steroidogenesis, intracellular signaling and cumulus expansion through PKA which modulates these functions through optimization of ERK1/2 phosphorylation and coordination of calcium signaling. These findings have implications for development of new strategies for improving oocyte in vitro maturation leading to better developmental competence. cumulus cells; cyclic AMP; cell signaling; oocyte maturation; transcriptomics; PKA; ERK1/2 FOLLICULOGENESIS IS CHARACTERIZED by cumulus-oocyte communication, which heralds better oocyte competence. This communication is mediated by gap junctions and affects accumulation of maternal factors within the oocyte that are essential to support early embryonic development (49). Also, through gap junctions, cumulus cells transfer cyclic adenosine 3=5=-monophosphate (cAMP) to the oocyte where one role of cAMP is to maintain arrest at meiotic prophase-I (12, 50). Oocyte resumes meiotic division (oocyte maturation) either in response to preovulatory luteinizing hormone (LH) surge or on its removal from its follicular environment (13,18). Additionally, a decline in intracellular cAMP can induce oocyte meiotic resumption, which presages a progressive closure of cumulusoocyte cross talk and transfer of maternal factors t...

The use of pituitary adenylate cyclase-activating polypeptide in the pre-maturation system improves in vitro developmental competence from small follicles of porcine oocytes

“…The gene is also important to ROS regulation, as well as inhibition of apoptosis and proliferation [36,37]. However, in contrast with earlier work showing that cAMP modulators increased HK2 transcript levels [26], we found that the pre-IVM group had significantly lower HK2 expression than the MF group, regardless of PACAP treatment. Our results could be attributable differences in follicle size, culture period, and cAMP-modulator type, all factors that influence the effectiveness of HK2 as an apoptosis indicator.…”

“…In mice, PACAP treatment during IVM improves cumulus expansion because PACAP contributes to cAMP response element-binding protein (CREB) phosphorylation through the cAMP/PKA pathway [21], and CREB is important to HAS2 expression [24,25]. Indeed, other cAMP modulators have generally increased HAS2 expression through the same pathway [26]. Moreover, cAMP-modulator treatment can immediately upregulate extracellular-matrix-formation genes during the pre-IVM stage, although effectiveness differs across modulator type [9].…”

Biphasic in vitro maturation with C-type natriuretic peptide enhances the developmental competence of juvenile-goat oocytes

“…Mitochondrial number and activity are also enhanced [10,22], which are additionally related to oocyte competence [26,27]. Lastly, cAMP-modulated IVM up-regulates genes involved in cell communication and metabolism, steroidogenesis and formation of extracellular matrix in cumulus cells [28], all of which are likely to reflect improved oocyte competence.…”

Cilostazol Improves Developmental Competence of Pig Oocytes by Increasing Intraoocyte Cyclic Adenosine Monophosphate Level and Delaying Meiotic Resumption

“…; Khan et al. ). These effects of cAMP might have augmented oocyte maturation, leading to better developmental competence.…”

“…This might have been attributed to the prevention of spontaneous premature meiotic resumption and early degradation of cAMP by inhibiting PDE3A activity after CLZ treatment (Albuz et al 2010). Conversely, cAMP has been shown to be involved in steroidogenesis, cell metabolism and cumulus cell expansion during oocyte maturation through protein kinase A (Chen et al 2009;Khan et al 2015). These effects of cAMP might have augmented oocyte maturation, leading to better developmental competence.…”