Cryopreservation of metaphase II human oocytes effects mitochondrial membrane potential: implications for developmental competence
Cryopreservation of metaphase II human oocytes effects mitochondrial membrane potential: implications for developmental competence
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DOI：
10.1093/humrep/deh313
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发表时间：
2004-08-01
影响因子：
6.1
通讯作者：
Toledo, AA
中科院分区：
文献类型：
--
作者：
Jones, A;Van Blerkom, J;Toledo, AA
背景技术背景：来自解冻的MII人类卵母细胞的胚胎的当前结果显著低于冷冻保存在原核阶段的胚胎。在这里，我们研究了冻融是否与卵母细胞线粒体极性（DeltaPsim）的变化，可以通过改变ATP水平或细胞质调节细胞内Ca 2+的能力来影响竞争力。方法：新鲜和解冻的未授精和未受精的MII卵母细胞用DeltaPsim特异性探针JC-1染色以检测高极化线粒体簇（J聚集体阳性），并用Ca 2+特异性探针Fluo-4染色以测量该阳离子的细胞内水平的变化。直接测量每个卵母细胞的ATP含量，并用皮质颗粒特异性探针观察皮质颗粒。研究结果：新鲜和解冻的MII卵母细胞之间存在显着差异的皮质周围的J-聚集体荧光和细胞质的能力，以增加游离钙离子载体曝光。ATP含量无显着差异，测定和冷冻保存与皮质颗粒的明显释放无关。结论：解冻卵母细胞中高DeltaPsim的不可逆损失可能与受精后Ca 2+信号传导的缺陷有关，并可能对正常胚胎发生产生下游后果。
BACKGROUND: Current outcome results with embryos derived from thawed MII human oocyes are significantly lower than with embryos cryopreserved at the pronuclear stage. Here, we investigated whether freezing-thawing was associated with changes in oocyte mitochondrial polarity (DeltaPsim) that could influence competence by altering ATP levels or the ability of the cytoplasm to regulate intracellular Ca2+. METHODS: Fresh and thawed uninseminated and unfertilized MII oocytes were stained with the DeltaPsim-specific probe JC-1 to detect clusters of high-polarized mitochondria (J-aggregate positive) and with the Ca2+- specific probe Fluo-4 to measure changes in intracellular levels of this cation. ATP content per oocyte was measured directly and cortical granules were visualized with a cortical granule-specific probe. RESULTS: A significant difference between fresh and thawed MII oocytes existed for pericortical J-aggregate fluorescence and for the ability of the cytoplasm to increase free Ca2+ in response to ionophore exposure. No significant difference in ATP contents was measured and cryopreservation was not associated with an apparent release of cortical granules. CONCLUSION: Irreversible loss of high DeltaPsim in thawed oocytes may be associated with defects in Ca2+ signalling after insemination and could have downstream consequences for normal embryogenesis.