Na+/H+ exchanger-3 is involved in mouse blastocyst formation
Na+/H+ exchanger-3 is involved in mouse blastocyst formation
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DOI：
10.1002/jez.a.90
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发表时间：
2004-09-01
影响因子：
2.8
通讯作者：
Murata, Y
中科院分区：
文献类型：
--
作者：
Kawagishi, R;Tahara, M;Murata, Y
小鼠囊胚由滋养外胚层、内细胞团和充满液体的腔（囊胚腔）组成。该空腔的形成和随后的扩张对于内细胞群的进一步分化和成功植入非常重要。以前的工作提供了证据表明，矢量运输Na+和Cl-离子通过滋养外胚层。进入囊胚腔产生渗透梯度，驱使液体穿过上皮。由于Na+/H+交换器（NHE）的活性被认为是促进经外胚层Na+通量的交换器，因此确定了NHE在小鼠囊胚腔发育中的功能作用。在存在亚型特异性NHE抑制剂的情况下培养胚胎，以检查NHE在囊胚腔发育中的作用。当2-细胞期胚胎连续用NHE-1的特异性抑制剂cariporide处理时，胚胎超过8-细胞期并变成囊胚。然而，在存在NHE-3的特异性抑制剂S3226的情况下，2-细胞期胚胎发育到桑椹胚期，但囊胚的形成以剂量依赖性方式受到抑制。Cariporide不抑制桑椹胚阶段囊胚腔的形成，而S3226则抑制该过程。S3226还降低了转移到对照培养基时细胞松弛素D塌陷的囊胚的再扩张率。免疫荧光研究表明，NHE-3检测到的滋养外胚层的细胞膜附近，特别是在顶端细胞边缘的滋养外胚层。这些结果表明，NHE-3可能参与胚泡形成。(C)2004威利-利斯公司
The mouse blastocyst consists of the trophectoderm, the inner cell mass, and a fluid-filled cavity, the blastocoel. Formation and subsequent expansion of this cavity is important for further differentiation of the inner cell mass and successful implantation. Previous work provided evidence that vectorial transport of Na+ and Cl- ions through the trophectoderm. into the blastocoel generates an osmotic gradient that drives fluid across this epithelium. As the activity of the Na+/H+ exchanger (NHE) has been implicated as the exchanger responsible for facilitating the transtrophectodermal Na+ flux, the functional role of NHE in mouse blastocoel development was determined. Embryos were cultured in the presence of subtype-specific NHE inhibitors to examine the role of NHEs in blastocoel development. When 2-cell stage embryos were treated continuously with a specific inhibitor of NHE-1, cariporide, the embryos passed beyond the 8-cell stage and became blastocysts. However, in the presence of a specific inhibitor of NHE-3, S3226, the 2-cell stage embryos developed to the morula stage but formation of the blastocyst were inhibited in a dose-dependent manner. Cariporide did not inhibit the formation of the blastocoel cavity from the morula stage whereas S3226 did inhibit that process. S3226 also reduced the rate of re-expansion of blastocysts collapsed by cytochalasin D upon transfer to the control medium. An immunofluorescence study showed that NHE-3 was detected in the vicinity of the cell membrane of the trophectoderm, especially in the apical cell margins of the trophectoderm. These results suggest that NHE-3 is likely involved in blastocyst formation. (C) 2004 Wiley-Liss, Inc.