Understanding hypoxia-induced gene expression in early development: In vitro and in vivo analysis of hypoxia-inducible factor 1-regulated zebra fish insulin-like growth factor binding protein 1 gene expression
Understanding hypoxia-induced gene expression in early development: In vitro and in vivo analysis of hypoxia-inducible factor 1-regulated zebra fish insulin-like growth factor binding protein 1 gene expression
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DOI：
10.1128/mcb.26.3.1142-1155.2006
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发表时间：
2006-02-01
影响因子：
5.3
通讯作者：
Duan, CM
中科院分区：
文献类型：
--
作者：
Kajimura, S;Aida, K;Duan, CM
胰岛素样生长因子结合蛋白1（IGFBP-1）是一种缺氧诱导基因，在缺氧应激下调节胚胎生长发育中发挥重要作用。胚胎组织中缺氧诱导 IGFBP-1 基因表达的分子机制尚不清楚。在这里，我们报道缺氧诱导因子 1 (HIF-1) 途径在早期胚胎发生中建立并介导缺氧诱导的 IGFBP-1 表达。缺氧增加了斑马鱼胚胎中 HIF-1 的活性，HIF-1 α 过表达或 CoCl2 处理导致 IGFBP-1 表达升高。尽管斑马鱼 IGFBP-1 启动子含有 13 个共有的缺氧反应元件 (HRE)，但缺失和突变分析表明，只有位于 -1090/-1086 的 HRE 是缺氧和 HIF-1 诱导所必需的。进一步的实验表明，有一个 HIF-1 辅助序列 (HAS) 仅与功能性 HRE 相邻。该 HAS 的突变大大降低了 IGFBP-1 启动子对缺氧和 HIF-1 的反应性。 HAS 不直接与 HIF-1 结合，也不影响 HRE 与 HIF-1 的结合。 HAS 与核蛋白结合，并且这种 HAS 结合活性会因缺氧而降低。这些结果表明，HIF-1 通过选择性地与 -1090/-1086 HRE 及其邻近的 HAS 相互作用来介导早期发育中缺氧诱导的 IGFBP-1 基因表达。
Insulin-like growth factor binding protein 1 (IGFBP-1) is a hypoxia-inducible gene that plays an important role in regulating embryonic growth and development under hypoxic stress. The molecular mechanisms underlying hypoxia-induced IGFBP-1 gene expression in the embryonic tissues are not well understood. Here we report that the hypoxia-inducible factor 1 (HIF-1) pathway is established in early embryogenesis and mediates hypoxia-induced IGFBP-1 expression. Hypoxia increased the HIF-1 activity, and HIF-1 alpha overexpression or CoCl2 treatment resulted in elevated IGFBP-1 expression in zebra fish embryos. Although the zebra fish IGFBP-1 promoter contains 13 consensus hypoxia response elements (HREs), deletion and mutational analysis revealed that only the HRE positioned at -1090/-1086 is required for the hypoxia and HIF-1 induction. Further experiments revealed that there is an HIF-1 ancillary sequence (HAS) adjacent only to the functional HRE. Mutation of this HAS greatly reduced the responsiveness of the IGFBP-1 promoter to hypoxia and HIF-1. The HAS does not directly bind to HIF-1 or affect the binding of the HRE to HIF-1. The HAS is bound to a nuclear protein(s), and this HAS binding activity is reduced by hypoxia. These results suggest that HIF-1 mediates hypoxia-induced IGFBP-1 gene expression in early development by selectively interacting with the -1090/-1086 HRE and its adjacent HAS.