Characterization and localization of side population (SP) cells in zebrafish kidney hematopoietic tissue
Characterization and localization of side population (SP) cells in zebrafish kidney hematopoietic tissue
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DOI：
10.1182/blood-2007-08-104299
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发表时间：
2008-02-01
期刊：
影响因子：
20.3
通讯作者：
Nakanishi, Teruyuki
中科院分区：
文献类型：
--
作者：
Kobayashi, Isao;Saito, Kazuyuki;Nakanishi, Teruyuki
我们先前在流式细胞仪分析中发现，硬骨肾造血组织中存在特殊的Hoechst染料外流模式的侧群(SP)细胞，并且肾脏SP细胞富含造血干细胞(HSCs)。ABCG2/ABCG2是一种ATIP结合盒(ABC)转运蛋白，被认为与哺乳动物HSCs的Hoechst染料外流活性有关。在本研究中，我们研究了ABCG2在斑马鱼(Danio Rerio)肾脏SP细胞中的表达和功能。虽然斑马鱼基因组中有4个相似的ABCG2拷贝(zAbcg2a、b、c和d)，但zAbcg2a和zAbcg2c在肾脏SP细胞中表达。将zAbcg2a和zAbcg2c导入COS-7细胞，发现zAbcg2a与SP表型直接相关。这些结果表明，zAbcg2a是斑马鱼HSCs的一个有用的标记。肾组织原位杂交显示，zAbcg2a阳性细胞散在分布于肾小管表面，与肾小管上皮细胞紧密结合。这一结果表明，硬骨鱼HSC附着在肾小管表面，肾小管上皮细胞是硬骨鱼HSC生态位的关键组成部分。
We previously showed that side population (SP) cells, characterized by specific Hoechst dye efflux pattern in flow cytometric analysis, were present in teleost kidney hematopoietic tissue, and that kidney SP cells were enriched in hematopoietic stem cells (HSCs). ABCG2/Abcg2 is an ATIP-binding cassette (ABC) transporter that is known to be associated with Hoechst dye efflux activity of mammalian HSCs. In the present study, we examined the expression and function of Abcg2 in kidney SP cells from zebrafish (Danio rerio). Although the zebrafish genome has 4 paralogous copies of ABCG2 (zAbcg2a, b, c, and d), zAbcg2a and zAbcg2c mRNA was expressed in kidney SP cells. Transfection of COS-7 cells with zAbcg2a and zAbcg2c showed that zAbcg2a was directly associated with the SP phenotype. These results indicate that zAbcg2a mRNA is a useful marker for zebrafish HSCs. In situ hybridization in kidney tissue showed that zAbcg2a-positive cells were sporadically localized on the surface of renal tubules, and tightly adhered to renal tubule epithelial cells. This result suggests that teleost HSCs adhere to the surface of renal tubules, and that renal tubule epithelial cells are a key component of HSC niche in teleosts.