FSH and LH receptors are differentially expressed in cumulus cells surrounding developmentally competent and incompetent mouse fully grown antral oocytes

Abstract

Cumulus cells (CCs) maintain strict functional relationships with the enclosed antral oocyte and are thought to reflect its developmental competence. Several studies have described a correlation between CC gene expression and oocyte quality. Herein, we tested whether CC-specific FSH and LH receptors (FSHR and LHR, respectively) are differentially expressed in CCs enclosing developmentally competent or incompetent oocytes. To this end, mouse fully grown cumulus-oocyte complexes were isolated and their CCs and oocytes analysed separately. Based on their chromatin organisation, oocytes were classified as those with a surrounded nucleolus (SN) or a non-surrounded nucleolus (NSN), the former being developmentally competent, whereas the latter arrest at the 2-cell stage. The CCs were then analysed to compare the pattern of expression of the Fshr and Lhr genes and their proteins. Quantitative reverse transcription-polymerase chain reaction analysis revealed that only Lhr is significantly differentially expressed. Immunofluorescence analysis revealed that both FSHR and LHR proteins are significantly upregulated in CCs surrounding oocytes arrested at the 2-cell stage, reflecting their developmental incompetence.

Temporal expression of cumulus cell marker genes during in vitro maturation and oocyte developmental competence

“…FSH and LH play important roles in the regulatory mechanisms of oocyte maturation through their binding to specific receptors (LHR and FSHR), which are expressed on the surface of CC [8,9,40]. A significant downregulation in the expression of LHR and FSHR in the CC of the poor oocytes at the completion of IVM was evident in the current study.…”

“…The expression of gremlin 1 (GREM1), hyaluronan synthase 2 (HAS2), prostaglandin-endoperoxide synthase 2 (PTGS2), and steroidogenic acute regulatory protein (STAR) genes in CC correlates with the developmental ability of oocytes and morphology of embryos [5][6][7]. The receptors of FSH and LH are expressed in CC [8,9], and it is proposed that LH contributes towards oocyte maturation exclusively through the cumulus expressed receptors [10,11]. The cumulus expression of B-cell CLL/lymphoma 2 (BCL2) and BCL2-associated X protein (BAX) genes has been found to be associated with the development of oocytes [12,13].…”

Mitochondrial Function in Modulating Human Granulosa Cell Steroidogenesis and Female Fertility

“…The characterization of the granulosa and cumulus cells by flow cytometry enabled the blood cells in the follicular fluids to be easily removed, which was done with anti-human CD45 antibody-coated magnetic beads [52]. Moreover, we performed a positive selection marker of the FSH receptor, which is specifically expressed on the surface of cumulus cells, enabling their selection [53] and the distinguishing of granulosa and cumulus cells from blood cells.…”

PGRMC1 participates in late events of bovine granulosa cells mitosis and oocyte meiosis

“…Flow cytometry analysis was conducted in order to evaluate the percentage of cells at each cell cycle phase as previously described. 59 Cells were collected, fixed in 70% cold EtOH and kept at +4 C until essayed. For time-lapse analysis CTRL and PGRMC1 RNAi treated bGC were stained with 0.05 mg/ml of Hoechst 33342 for 30 minutes and then substituted with fresh medium and imaged on a biostation IM (Nikon).…”