Dithiothreitol prevents the spontaneous release of cortical granules in in vitro aged mouse oocytes by protecting regulatory proteins of cortical granules exocytosis and thickening the cortical actin cytoskeleton.

In assisted fertility protocols, in vitro culture conditions mimic physiological conditions to preserve gametes in the best conditions. After collection, oocytes are maintained in a culture medium inside the incubator until in vitro fertilization (IVF) is performed. This time outside natural and physiological conditions exposes oocytes to an oxidative stress that renders in vitro aging.

The light chain of tetanus toxin bound to arginine-rich cell-penetrating peptide inhibits cortical reaction in mouse oocytes.

Cortical reaction is a secretory process that occurs after a spermatozoon fuses with the oocyte, avoiding the fusion of additional sperm. During this exocytic event, the cortical granule membrane fuses with the oocyte plasma membrane. We have identified several molecular components involved in this process and confirmed that SNARE proteins regulate membrane fusion during cortical reaction in mouse oocytes.

Dehydroleucodine and xanthatin, two natural anti-inflammatory lactones, inhibit mast cell degranulation by affecting the actin cytoskeleton.

Actin remodeling is a critical regulator of mast cell secretion. In previous work, we have shown that dehydroleucodine and xanthatin, two natural α,β-unsaturated lactones, exhibit anti-inflammatory and mast cell stabilizing properties. Based on this background, this study aimed to determine whether the mast cell stabilizing action of these lactones is associated with changes in the actin cytoskeleton.

Live imaging of cortical granule exocytosis reveals that matured mouse oocytes are not fully competent to secrete their content.

Oocyte maturation does not entirely support all the nuclear and cytoplasmic changes that occur physiologically, and it is poorly understood whether maturation affects the competence of cortical granules to secrete their content during cortical reaction. Here, we characterize cortical granule exocytosis (CGE) in live mouse oocytes activated by strontium chloride using the fluorescent lectin FITC-LCA. We compared the kinetic of CGE between ovulated ( matured, IVO) and matured (IVM) mouse oocytes.