Fujishima Ayaka, Takahashi Kazumasa, Goto Mayumi, Fujishima Akiko, Hirakawa Takeo, Iwasawa Takuya, Shirasawa Hiromitsu, Kumazawa Yukiyo, Terada Yukihiro
Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan.
PLoS One. 2025 Apr 30;20(4):e0322286. doi: 10.1371/journal.pone.0322286. eCollection 2025.
The developmental process of the mammalian blastocyst involves the intricate interplay of cellular and molecular mechanisms, including electrolyte dynamics within the trophectoderm (TE). We hypothesized that sodium (Na+) is actively transported from the TE into the blastocyst cavity, driving water influx and promoting blastocyst expansion. In this study, we investigated the dynamics of Na+ concentration in the TE of mouse embryos using sodium-binding benzofuran isophthalate (SBFI), a dual-wavelength Na+-sensitive fluorescent indicator. Observations revealed three distinct patterns of Na+ dynamics, each correlating with variations in blastocyst cross-sectional area and developmental outcomes. Embryos exhibiting an initial decrease followed by stabilization of Na+ concentration (Group A) demonstrated the highest rates of hatching, suggesting a relationship between Na+ flux and successful embryonic development. In contrast, embryos with transient increases (Group B) displayed reduced hatching rates and developmental progression. Further, the inhibition of Na+/K+-ATPase activity disrupted Na+ flux and blastocyst cavity expansion, emphasizing its critical role in blastocyst formation. This study highlights the potential of dual-wavelength imaging for elucidating electrolyte dynamics in preimplantation embryos and its implications for optimizing embryo culture systems in reproductive medicine.
哺乳动物囊胚的发育过程涉及细胞和分子机制的复杂相互作用,包括滋养外胚层(TE)内的电解质动态变化。我们假设钠(Na+)从TE被主动转运到囊胚腔中,驱动水的流入并促进囊胚扩张。在本研究中,我们使用钠结合苯并呋喃异酞酸酯(SBFI),一种双波长Na+敏感荧光指示剂,研究了小鼠胚胎TE中Na+浓度的动态变化。观察结果揭示了三种不同的Na+动态模式,每种模式都与囊胚横截面积和发育结果的变化相关。Na+浓度最初下降随后稳定的胚胎(A组)孵化率最高,表明Na+通量与胚胎成功发育之间存在关联。相比之下,Na+浓度短暂升高的胚胎(B组)孵化率和发育进程降低。此外,抑制Na+/K+-ATP酶活性会破坏Na+通量和囊胚腔扩张,强调了其在囊胚形成中的关键作用。本研究突出了双波长成像在阐明植入前胚胎电解质动态变化及其对生殖医学中优化胚胎培养系统的意义方面的潜力。