Cooperative Effects of 17β-Estradiol and Oocyte-Derived Paracrine Factors on the Transcriptome of Mouse Cumulus Cells

Abstract

Oocyte-derived paracrine factors (ODPFs) and estrogens are both essential for the development and function of ovarian follicles in mammals. Cooperation of these two factors was assessed in vitro using intact cumulus-oocyte complexes, cumulus cells cultured after the removal of oocytes [oocytectomized (OOX) cumulus cells], and OOX cumulus cells cocultured with denuded oocytes, all in the presence or absence of 17β-estradiol (E2). Effects on the cumulus cell transcriptome were assessed by microarray analysis. There was no significant difference between the cumulus cell transcriptomes of either OOX cumulus cells cocultured with oocytes or intact cumulus-oocyte complexes. Therefore, oocyte-mediated regulation of the cumulus cell transcriptome is mediated primarily by ODPFs and not by gap junctional communication between oocytes and cumulus cells. Gene ontology analysis revealed that both ODPFs and E2 strongly affected the biological processes associated with cell proliferation in cumulus cells. E2 had limited effects on ODPF-regulated biological processes. However, in sharp contrast, ODPFs significantly affected biological processes regulated by E2 in cumulus cells. For example, only in the presence of ODPFs did E2 significantly promote the biological processes related to phosphorylation-mediated signal transduction in cumulus cells, such as the signaling pathways of epidermal growth factor, vascular endothelial growth factor, and platelet-derived growth factor. Therefore, ODPFs and E2 cooperate to regulate the cumulus cell transcriptome and, in general, oocytes modulate the effects of estrogens on cumulus cell function.

Transcriptomic Diversification of Developing Cumulus and Mural Granulosa Cells in Mouse Ovarian Follicles1

“…Thus, there were three biological replicates of each sample. The samples were amplified and applied to Affymetrics 430V2 arrays by the Jackson Laboratory Gene Expression Service as described previously [19,34].…”

“…First, only the transcripts associated with GO terms and annotated with known biological or molecular functions are presented; the entire lists of transcripts have been deposited in the Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo, dataset GSE55845). Additional transcriptomic analyses showing the effects of ODPFs on cumulus cell transcripts and on the effect of Gdf9 þ/À Bmp15 À/À double mutation were deposited previously (GSE47967) [34] and (GSE7225) [19], respectively. Second, the top 50 transcripts exhibiting the greatest fold differences within the contrast are presented.…”

“…Two approaches were used to test this: 1) comparison of the transcripts expressed at higher levels in freshly isolated cumulus cells with those found previously to be stimulated in cumulus cells by ODPFs in vitro [34] and 2) comparison of the higher cumulus cell transcripts with those found previously to be lower in cumulus cells of mutants deficient in the ODPFs GDF9 and BMP15 versus wild-type (WT) cumulus cells in vivo [35].…”

Oocyte-dependent activation of MTOR in cumulus cells controls the development and survival of cumulus-oocyte complexes

“…A similar mechanism has been proposed for oocyte control of the differential expression of many other functionally important genes within antral follicles (Eppig et al, 1997;Eppig et al, 2005;Su et al, 2008;Sugiura et al, 2005) and to direct the global patterns of gene expression in granulosa cells (Diaz et al, 2007b;Emori et al, 2013;Wigglesworth et al, 2015). Although the actual concentration of GDF9 in follicular fluid is unlikely to be as high as the dose (500 ng/ ml) that we have observed here to be effective in regulating Ddit4l expression and MTOR activation, genetic studies clearly show that both GDF9 and BMP15 are present in follicular fluid and function in synergy .…”

Soy Promotes Juvenile Granulosa Cell Tumor Development in Mice and in the Human Granulosa Cell Tumor-Derived COV434 Cell Line1

“…Although steroid hormones such as estradiol contribute to the growth of cumulus cells in cooperation with oocyte-derived factors by negatively affecting cell death [50,51], its role in GCT has been understudied. Both estrogen receptor isoforms ESR1 and ESR2 are expressed in tumors of stromal origin, with ESR2 being expressed predominantly in granulosa cell tumors [36].…”