A Role of Lipid Metabolism during Cumulus-Oocyte Complex Maturation: Impact of Lipid Modulators to Improve Embryo Production

Figure 4

Hypothetical model for the effects of forskolin and trans-10, cis-12 conjugated linoleic acid (CLA) in the regulation of oocyte lipid metabolism and developmental competence acquisition: red colour and solid arrows, stimulation of cAMP intracellular levels, PKA and MAPK pathways by forskolin (see text for details); potential mechanisms of CLA action are also in red but illustrated by dashed arrows, including stimulation of PKA and MAPK pathways interfering with LD lipolysis, control of oocyte gene expression, and protein synthesis, namely, perilipins. Left, the cytoplasmic membrane and different events that are crucial for suitable oocyte maturation are represented in blue. R and G are the transmembrane G-protein-coupled receptor activated by different hormones or EGF (blue triangle) during this process. Red arrows illustrate the activity of different intracellular messengers and fatty acids regulating oocyte lipid metabolism and quality. DAG, diacylglycerol, DdGA, diradilglyceride, PIP2, phosphatidylinositol 4,5 bisphosphate, IP3, inositol 1,4,5-trisphosphate; PKA, protein kinase A; PKC, protein kinase C, MAPK, mitogen protein kinase; AC, adenylyl cyclase; HSL, hormone sensitive lipase; MGL, monoglyceride lipase; P, perilipin protein; LD, lipid droplet; NEFA, nonesterified fatty acids.