Advanced Maternal Age Deteriorates the Developmental Competence of Vitrified Oocytes in Mice

Abstract

Advanced maternal age (AMA) is known to be related to the decrease in the quality and quantity of oocytes. Oocyte vitrification is now considered an established assisted reproductive technology for fertility preservation. However, it remains unclear whether the oocytes in older women are more sensitive to various insults during vitrification. Thus, we evaluated whether AMA affects cellular and molecular features and developmental outcomes of oocytes after vitrification in mice. The oocytes were grouped as young fresh (YF), young vitrified/warmed (YV), aged fresh (AF), and aged vitrified/warmed (AV). The survival rate of AV oocytes was significantly lower than that of YV oocytes. The rates of fertilization, cleavage, and blastocyst formation of AV oocytes were significantly lower than those of other groups. AV oocytes were represented as aberrations in mitochondria distribution, microvacuole size, and autophagosome formation, leading to delayed embryo development in mice. This delay was associated with a reduced number of total cells and trophectoderm in the blastocyst developed from AV oocytes. Collectively, AMA exaggerates the vulnerability of oocytes to cryo-damage that occurs during vitrification in mice, suggesting that the current vitrification protocols optimized for oocytes from young females should be modified for oocytes from aged women.

Melatonin loaded PLGA nanoparticles effectively ameliorate the in vitro maturation of deteriorated oocytes and the cryoprotective abilities during vitrification process

“…Oocyte vitrification and thawing were perfomred according to the methods described in ref. 49 and 50 with minor modifications. Briefly, the oocytes were placed in equilibration solution (7.5% ethylene glycol (EG), 7.5% DMSO, 20% BSA in M2 medium) for 3 min and then transferred to vitrification solution (15% EG, 15% DMSO, 0.5 M Sucrose in M2 medium) for 60 s. Finally, the oocytes were transferred to a cryovial and then immediately plunged into LN2 and stored in the LN2 tank for 0.25 hours or 0.5 hours.…”

Mitochondria Transfer from Adipose Stem Cells Improves the Developmental Potential of Cryopreserved Oocytes

“…In cryopreserved oocytes, the distribution and dynamics of mitochondria are disturbed, and the membrane potential is lowered, resembling the condition of aged oocytes [ 47 ]. It has also been reported that human and animal oocytes’ mitochondrial structure and function are seriously diminished following cryopreservation [ 17 , 48 , 49 , 50 ].…”

Comparing the effects of a commercial and a prototype vitrification medium on meiotic spindle morphology and survival rate of mouse oocytes

“…Inversely, higher SR (92-98%) of vitrified-warmed oocytes using the combination of EG plus DMSO, and sucrose as cryoprotectants were reported in B6D2F1 mice ( Gomes et al ., 2008 ; Zhou et al ., 2016 ). In C57BL/6J strain, Lee et al . (2021) reported a SR of 94.2% of vitrified-warmed oocytes.…”