|
Comment |
Progesterone Receptor-Induced Gene Expression in Primary Mouse Granulosa Cell Cultures. Sriraman V et al. The progesterone receptor (PGR) is induced by LH in granulosa cells of preovulatory follicles and the PGR-A isoform is essential for ovulation based on the phenotypes of Pgr isoform specific knockout mice. Although several genes regulated by PGR-A in vivo have been identified, whether these genes are primary targets of PGR-A or if their expression also depends on other signaling molecules that are induced by the LH surge have not been resolved. Therefore, to identify genes that are either induced or repressed by PGR in the absence of LH mediated signaling cascades, we infected primary cultures of mouse granulosa cells with either PGR-A or PGR-B adenoviral vectors without or with R5020 as a PGR ligand. Total RNA was extracted from infected cells at 16 h and analyzed by Affymetrix Mouse 430 2.0 microarrays. PGR-A in the presence or absence of ligand significantly induced ~50 genes 2-fold or more (LPE test at P-value <= 0.01). Fewer and different genes were induced by PGR-B in the absence of ligand. Edn1, Apoa1 and Cited1 were primarily regulated by PGR-A as verified by additional RT-PCR analyses, suppression by the PGR antagonist RU486 and by the lack of induction by protein kinase A, protein kinase C or EGF-like factors pathways. PGR regulation of these genes was confirmed further by gene expression analyses in hormonally-primed Pgr mutant mouse ovaries. Because Edn1, Apoa1 and Cited1 are known to regulate angiogenesis, PGR may impact the neovascularization of follicles that is initiated with ovulation.
Transcriptome analysis of FSH and FSH variant stimulation in granulosa cells from IVM patients reveals novel regulated genes. Perlman S et al. FSH is crucial for oocyte maturation and fertility and is the main component in infertility treatment in assisted reproduction. The granulosa cells expressing the FSH receptor interact with the oocyte and provide nourishing substrates controlling the oocyte maturation. Thus, transcriptome analysis of granulosa cells stimulated by FSH is of major importance in understanding the communication between oocytes and granulosa cells. In this study, gene expression profiles were assessed in human granulosa cells from normal cycling in vitro maturation (IVM) patients using oligonucleotide gene chips. Granulosa cells were stimulated for 2 h with either FSH or a previously generated glycosylated FSH variant (FSH1208) that exhibited increased in vivo activity because of prolonged half-life. The analysis identified 74 significantly FSH/FSH1208 regulated genes. Amongst these were well known FSH regulated genes as well as genes not previously described to be important in the FSH signalling pathway. These novel FSH regulated genes include transcription factors [cAMP responsive element modulator (CREM)/inducible cAMP early repressors (ICER), GATA 6, ZFN 361, Bcl11a, CITED1 and TCF 8] and other regulatory proteins and enzymes (IGF-BP3, syntaxin and PCK1) possibly important for oocyte/granulosa cell interaction and function. Array data were validated for 13 genes by northern blots or RT-PCR. Furthermore, no significant differences in gene regulation were detected between the two FSH analogs. This work uncovers novel data important for understanding the folliculogenesis. Furthermore, the results suggest that FSH1208 has a gene expression profile like FSH and thus, in the light of known prolonged in vivo activity, might be a candidate for improved infertility treatment.
|