Role of glucose in mouse preimplantation embryo development
Role of glucose in mouse preimplantation embryo development
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DOI：
10.1002/mrd.1080400407
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发表时间：
1995-04
影响因子：
2.5
通讯作者：
K. Martin;H. Leese
中科院分区：
文献类型：
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作者：
K. Martin;H. Leese
小鼠植入前胚胎在早期发育阶段优先消耗丙酮酸，然后葡萄糖成为囊胚中的主要能量底物。为了研究在发育后期转向葡萄糖利用的重要性，将 F1 杂交小鼠 (CBA/Ca × C57BL/6) 的小鼠胚胎从单细胞阶段和双细胞阶段（分别在 hCG 后 22 小时和 46 小时）在含有 0.33 mM 丙酮酸和 5 或 23 mM D+L-乳酸的改良培养基 M16 中培养 5 天，在存在和不存在 1 mM 葡萄糖的情况下（分别为 M16+G 和 M16-G）。在此期间还测定了养分吸收。在 hCG 后 94 或 118 小时，将 M16-G 中培养的一些胚胎转移至 M16+G。 Embryos cultured from the two‐cell stage in M16+G exhibited the characteristic fall in pyruvate consumption between the morula and the blastocyst stage; M16-G 中从双细胞阶段培养的细胞通过消耗越来越多的丙酮酸来补偿葡萄糖的缺乏，从 hCG 后 58 小时的 2.78 pmol/胚胎/小时到 hCG 后 154 小时的 5.21 pmol/胚胎/小时。然而，该组胚胎发育至囊胚阶段的百分比、孵化率和囊胚细胞数量（50.6 ± 2.5 [28] vs. 105 ± 3.8 [37]）均较低。当 hCG 后 94 或 118 小时暴露于葡萄糖时，M16-G 中双细胞阶段培养的胚胎很容易优先消耗葡萄糖而不是丙酮酸，尽管没有观察到丙酮酸消耗的特征性下降。在M16-G中连续培养的单细胞胚胎只能发育到桑葚胚阶段，之后就会退化。在这些胚胎中，丙酮酸在 hCG 后 22 至 94 小时之间很容易被消耗，然后从 hCG 后 83 小时的 2.77 pmol/胚胎/小时下降到 hCG 后 130 小时的 0.045 pmol/胚胎/小时。在 hCG 后 94 和 118 小时将这些胚胎转移至 M16+G 并不支持发育至孵化囊胚阶段。结果表明，F1 杂交小鼠 (CBA/Ca × C57BL/6) 的植入前胚胎只需在 hCG 后 22 至 94 小时之间暴露于葡萄糖中不到 24 小时，即可在体外从桑葚胚发育至囊胚阶段。然而，暴露时间需要增加到 24 至 72 小时之间，以便囊胚细胞数量达到控制水平。桑葚胚阶段之前葡萄糖的重要性可能与合成糖原供以后使用的需要有关。如果满足了对葡萄糖的强制性要求，胚胎就能够在发育后期在缺乏葡萄糖的情况下利用丙酮酸。这些结果表明，小鼠植入前胚胎可以在一定程度上通过代谢来适应外部环境的变化。 © 1995 Wiley-Liss, Inc.
Mouse preimplantation embryos consume pyruvate preferentially during the early developmental stages, before glucose becomes the predominant energy substrate in the blastocyst. To investigate the importance of the switch to glucose utilization at the later developmental stages, mouse embryos from F1 hybrid mice (CBA/Ca × C57BL/6) were cultured from the one‐and two‐cell stages (22 and 46 h post hCG, respectively) for 5 days in a modified medium, M16, containing 0.33 mM pyruvate and 5 or 23 mM D+L‐lactate, in the presence and absence of 1 mM glucose (M16+G and M16‐G, respectively). Nutrient uptakes were also determined over this time. Some embryos cultured in M16‐G were transferred to M16+G at 94 or 118 h post hCG. Embryos cultured from the two‐cell stage in M16+G exhibited the characteristic fall in pyruvate consumption between the morula and the blastocyst stage; those cultured from the two‐cell stage in M16‐G compensated for the lack of glucose by consuming increasing amounts of pyruvate, from 2.78 pmol/embryo/h at 58 h post hCG to 5.21 pmol/embryo/h at 154 h post hCG. However, the percentage of embryos developing to the blastocyst stage, the hatching rate, and blastocyst cell numbers (50.6 ± 2.5 [28] vs. 105 ± 3.8 [37]) were all lower in this group. When exposed to glucose at 94 or 118 h post hCG, embryos cultured from the two‐cell stage in M16‐G readily consumed glucose in preference to pyruvate, although the characteristic fall in pyruvate consumption was not observed. One‐cell embryos cultured continuously in M16‐G were only able to develop to the morula stage, after which time they degenerated. In these embryos pyruvate was readily consumed between 22 and 94 h post hCG, before falling from 2.77 pmol/embryo/h at 83 h post hCG to 0.045 pmol/embryo/h at 130 h post hCG. Transfer of these embryos to M16+G at 94 and 118 h post hCG did not support development to the hatching blastocyst stage. The results show that mouse preimplantation embryos from F1 hybrid mice (CBA/Ca × C57BL/6) need only be exposed to glucose for less than 24 h between 22 and 94 h post hCG in order to develop from the morula to the blastocyst stage in vitro. However, the exposure time needs to be increased to between 24 and 72 h in order that blastocyst cell numbers reach control levels. The importance of glucose before the morula stage may relate to the need to synthesize glycogen for later use. If the obligatory requirement for glucose is fulfilled, embryos are able to utilize pyruvate in the absence of glucose at the later stages of development. These results show that the mouse preimplantation embryo can, to some extent, adapt metabolically to changes in its external environment. © 1995 Wiley‐Liss, Inc.