Université Clermont Auvergne, Inserm, Imagerie Moléculaire Et Stratégies Théranostiques, UMR 1240, Clermont-Ferrand, France.
Université de Toulouse, Toulouse, France.
Reprod Sci. 2024 Sep;31(9):2625-2636. doi: 10.1007/s43032-024-01596-7. Epub 2024 May 21.
Cryopreservation of in vitro matured oocytes is still considered as an experimental alternative to mature oocyte vitrification after ovarian stimulation. Here, we investigated whether rescue-IVM should be performed before or after vitrification. For this, 101 immature oocytes (germinal vesicle stage) from women undergoing ICSI were used. Oocytes were divided into three groups: freshly in vitro matured oocytes (IVM), freshly in vitro matured oocytes subsequently vitrified (IVM + VIT) and vitrified/warmed GV oocytes then in vitro matured (VIT + IVM). Oocyte maturation rates and kinetics were assessed using time-lapse technology. Spindle dimensions and polarity, chromosome alignment and cytoplasmic F-actin filament length and density were determined using confocal microscopy and quantitative image analyses. No differences in IVM rates (fresh IVM: 63.16% and IVM post-VIT: 59.38%, p = 0.72) and timings (17.73 h in fresh IVM, 17.33 h in IVM post-VIT, p = 0.72) were observed whether IVM is performed freshly or after vitrification. Meiotic spindles were shorter in VIT + IVM (10.47 µm vs 11.23 µm in IVM and 11.40 µm in IVM + VIT, p = 0.012 and p = 0.043) and wider in IVM + VIT (9.37 µm vs 8.12 µm in IVM and 8.16 µm VIT + IVM, p = 0.027 and p = 0.026). The length-to-width ratio was lower in vitrified groups (IVM + VIT: 1.19 and VIT + IVM: 1.26) compared to IVM (1.38), p = 0.013 and p = 0.014. No differences in multipolar spindle and chromosome misalignment occurrence and cytoplasmic F-actin filament length and density were observed between groups. Our results suggest vitrification before or after rescue-IVM does not seem to impair maturation rates and kinetics parameters but induces meiotic spindle alterations.
体外成熟卵母细胞的冷冻保存仍然被认为是卵巢刺激后卵母细胞玻璃化的一种实验替代方法。在这里,我们研究了在玻璃化之前还是之后进行挽救性 IVM 是否更好。为此,使用了 101 个正在接受 ICSI 的女性的未成熟卵母细胞(生发泡期)。卵母细胞分为三组:新鲜体外成熟卵母细胞(IVM)、新鲜体外成熟卵母细胞随后玻璃化(IVM+VIT)和玻璃化/加热GV 卵母细胞然后体外成熟(VIT+IVM)。使用时间 lapse 技术评估卵母细胞成熟率和动力学。使用共聚焦显微镜和定量图像分析评估纺锤体尺寸和极性、染色体排列以及细胞质 F-肌动蛋白丝长度和密度。无论是在新鲜状态下进行 IVM(新鲜 IVM:63.16%和 IVM 后 VIT:59.38%,p=0.72)还是在玻璃化后进行 IVM(新鲜 IVM:17.73 小时,IVM 后 VIT:17.33 小时,p=0.72),IVM 率和时间没有差异。在 VIT+IVM 中,减数分裂纺锤体更短(10.47 µm 与 IVM 中的 11.23 µm 和 IVM+VIT 中的 11.40 µm,p=0.012 和 p=0.043),在 IVM+VIT 中更宽(9.37 µm 与 IVM 中的 8.12 µm 和 VIT+IVM 中的 8.16 µm,p=0.027 和 p=0.026)。与 IVM 相比,玻璃化组的长度与宽度比更低(IVM+VIT:1.19 和 VIT+IVM:1.26),p=0.013 和 p=0.014。各组之间多极纺锤体和染色体错位的发生以及细胞质 F-肌动蛋白丝长度和密度没有差异。我们的结果表明,在玻璃化之前或之后进行挽救性 IVM 似乎不会损害成熟率和动力学参数,但会诱导减数分裂纺锤体改变。