High-Throughput Analysis of Ovarian Granulosa Cell Transcriptome

Abstract

The quality of follicular oocytes depends on interactions with surrounding granulosa cells. Development of molecular techniques and methods enables better understanding of processes underlying mammalian reproduction on cellular level. The success in reproductive biology and medicine in different species depends on reliable assessment of oocyte and embryo viability which presently mainly bases on embryo morphology. Although successful pregnancies have been achieved using this approach, its precision still should be improved and completed with other, more objective, and accurate assessment strategies. Global profiling of gene expression in follicular cumulus cells using microarrays is continuously leading to the establishment of new biomarkers which can be used to select oocytes with highest developmental potential. Even more potential applications and greater precision could be achieved using next generation sequencing (NGS) of granulosa and cumulus cell RNA (RNA-seq). However, due to the high cost, this method is not used as frequently as microarrays at the moment. In any case, high-throughput technologies offer the possibilities and advantages in ovarian somatic cell analysis on scale that has not been noted so far. The aim of this work is to present current directions and examples of global molecular profiling of granulosa cells and underline its impact on reproductive biology and medicine.

The Impact of Controlled Ovarian Stimulation Hormones on the Metabolic State and Endocannabinoid System of Human Cumulus Cells

“…Endocannabinoids also target the peroxisome proliferator-activated receptors (PPARs) [ 33 ]; in particular, through the activation of PPARα or PPARγ [ 34 ], AEA and 2-AG can modulate lipid and glucose metabolism. This aspect is crucial in cumulus cells, since one of their key functions in the follicle environment is to sustain the metabolic needs of the oocytes, which are not independent [ 35 , 36 , 37 ]. Granulosa and cumulus cells have a role in follicular lipid metabolism regulation, by oxidizing lipids and storing them in lipid droplets [ 38 ].…”

Gene Expression in Cumulus Cells and Oocyte Quality

“…Given the intimate connection between GCs and oocyte, it is clear that modifications in somatic components transcriptomes affect the oocyte functions and vice versa. The main approaches employed to study GCs transcriptome have been represented by microarray analysis and next-generation RNA sequencing [7]. These two approaches allow to study simultaneously thousands of transcripts and evidence the role of specific genes in normal and pathological oocyte development.…”

The activated DNA double-strand break repair pathway in cumulus cells from aging patients may be used as a convincing predictor of poor outcomes after in vitro fertilization-embryo transfer treatment

“…Cumulus cells, which are layers of specialized granulosa cells encircling oocytes, are thought to be closely related to the growth and meiotic maturation of oocytes, not only through supplying nutrients or signaling molecules to oocytes via gap junctions [ 1 , 2 ] but also via the protection of oocytes from adverse environments or factors [ 3 ]. Notably, increasing evidence has demonstrated that apoptosis in cumulus cells plays a mediating role in impairing oocyte developmental potential [ 4 – 6 ].…”