Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
Cell Mol Life Sci. 2011 Aug;68(16):2797-809. doi: 10.1007/s00018-010-0593-2. Epub 2010 Nov 24.
The present study using zebrafish as a model explores the role of isotocin, a homolog of oxytocin, in controlling ion regulatory mechanisms. Double-deionized water treatment for 24 h significantly stimulated isotocin mRNA expression in zebrafish embryos. Whole-body Cl(-), Ca(2+), and Na(+) contents, mRNA expressions of ion transporters and ionocyte-differentiation related transcription factors, and the number of skin ionocytes decreased in isotocin morphants. In contrast, overexpression of isotocin caused an increase in ionocyte numbers. Isotocin morpholino caused significant suppression of foxi3a mRNA expression, while isotocin cRNA stimulated foxi3a mRNA expressions at the tail-bud stage of zebrafish embryos. The density of P63 (an epidermal stem cell marker)-positive cells was downregulated by isotocin morpholinos and was upregulated by isotocin cRNA. Taken together, isotocin stimulates the proliferation of epidermal stem cells and differentiation of ionocyte progenitors by regulating the P63 and Foxi3a transcription factors, consequently enhancing the functional activities of ionocytes.
本研究以斑马鱼为模型，探讨了催产素同源物——缩宫素在调控离子调节机制中的作用。双去离子水处理 24 小时可显著刺激斑马鱼胚胎中缩宫素 mRNA 的表达。在缩宫素类似物突变体中，全身 Cl(-)、Ca(2+)和 Na(+)含量、离子转运体和离子细胞分化相关转录因子的 mRNA 表达以及皮肤离子细胞数量减少。相比之下，过量表达缩宫素会导致离子细胞数量增加。缩宫素类似物 MOR 显著抑制 foxi3a mRNA 的表达，而在斑马鱼胚胎的尾芽期，缩宫素 cRNA 刺激 foxi3a mRNA 的表达。P63（表皮干细胞标志物）阳性细胞的密度被缩宫素类似物 MOR 下调，被缩宫素 cRNA 上调。综上所述，缩宫素通过调节 P63 和 Foxi3a 转录因子，刺激表皮干细胞的增殖和离子细胞前体细胞的分化，从而增强离子细胞的功能活性。
