The role of GPR1 signaling in mice corpus luteum. Yang Y et al. (2016) Chemerin, a chemokine, plays important roles in immune responses, inflammation, adipogenesis, and carbohydrate metabolism. Our recent research has shown that chemerin has an inhibitory effect on hormone secretion from the testis and ovary. However, whether GPR1, the active receptor for chemerin, regulates steroidogenesis and luteolysis in the corpus luteum is still unknown. In this study, we established a PMSG-hCG superovulation model, a PGF2α luteolysis model, and follicle and corpus luteum culture models to analyze the role of chemerin signaling through GPR1 in the synthesis and secretion of gonadal hormones during follicular/luteal development and luteolysis. Our results, for the first time, show that chemerin and GPR1 are both differentially expressed in the ovary over the course of the estrous cycle, with highest levels in estrus and metestrus. GPR1 has been localized to granulosa cells, cumulus cells, and the corpus luteum by immunohistochemistry. In vitro, we found that chemerin suppresses human chorionic gonadotropin (hCG)-induced progesterone production in cultured follicle and corpus luteum and that this effect is attenuated significantly by anti-GPR1 mAb treatment. Furthermore, when the PI3K pathway was blocked, the attenuating effect of GPR1 mAb was abrogated. Interestingly, PGF2α induces luteolysis through activation of caspase-3, leading to a reduction in progesterone secretion. Treatment with GPR1 mAb blocked the PGF2α effect on caspase-3 expression and progesterone secretion. This study indicates that chemerin/GPR1 signaling directly or indirectly regulates progesterone synthesis and secretion during the processes of follicular development, corpus luteum formation, and PGF2a induced luteolysis.//////////////////
Expression regulated by
Comment
Ovarian localization
Oocyte, Cumulus, Granulosa, Luteal cells
Comment
Maternal gene transcription in mouse oocytes: genes implicated in oocyte maturation and fertilization. Cui XS et al. Maternal gene expression is an important biological process in oocyte maturation and early cleavage. To gain insights into oocyte maturation and early embryo development, we used microarray analysis to compare the gene expression profiles of germinal vesicle (GV)- and metaphase II (MII)-stage oocytes. The differences in spot intensities were normalized and grouped using the Avadis Prophetic software platform. Of the 12164 genes examined, we found 1682 genes with more highly expression in GV-stage oocytes than in MII-stage oocytes, while 1936 genes were more highly expressed in MII-stage oocytes (P<0.05). The genes were grouped on the basis of the Panther classification system according to their involvement in particular biological processes. The genes that were up-regulated in GV oocytes were more likely to be involved in protein metabolism and modification, the mitotic cell cycle, electron transport, or fertilization or belong to the microtubule/cytoskeletal protein family. The genes specifically upregulated in the MII oocytes were more likely to be involved in DNA replication, amino acid metabolism, or expression of G protein-coupled receptors and signaling molecules. Identification of genes that are preferentially expressed at particular oocyte maturation stages provides insights into the complex gene regulatory networks that drive oocyte maturation and fertilization. 8 fold decrease from GV to MII oocytes.