Metabolic exchanges between the oocyte and its environment: focus on lipids

Area of Science:

• Reproductive Biology
• Cellular Metabolism
• Lipidomics

Background:

• Ovarian follicle development and oocyte quality are critically dependent on precise fatty acid (FA) metabolism.
• The lipid composition within follicular compartments is increasingly recognized for its influence on oocyte quality.

Purpose of the Study:

• To review the role of lipids and their exchange within the ovarian follicle during oocyte maturation.
• To explore the involvement of lipid metabolism in follicular development and intra-follicular homeostasis.

Main Methods:

• Utilized lipidomics to analyze global lipid profiles in follicular cells and fluids at various physiological stages.
• Reviewed expression data to identify key actors in lipid metabolism across different follicular cell types (theca, granulosa, cumulus) and oocytes.

Main Results:

• Follicular fluid acts as a central mediator for lipid exchange between somatic cells and the oocyte via vesicular and non-vesicular transport of free and esterified fatty acids.
• Identified common and cell-specific regulators of fatty acid uptake, transport, lipid transformation, lipoprotein synthesis, and protein palmitoylation within the follicle.

Conclusions:

• Intra-follicular lipid metabolism and homeostasis are essential for oocyte growth, maturation, and the accumulation of lipids necessary for subsequent meiotic and early embryonic processes.
• The coordinated action of lipid metabolism actors ensures the oocyte is equipped for fertilization and early development.