Pax2 may play a role in kidney development by regulating the expression of TBX1
Pax2 may play a role in kidney development by regulating the expression of TBX1
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Pax2可能通过调节TBX1的表达在肾脏发育中发挥作用
DOI：
10.1007/s11033-014-3639-y
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发表时间：
2014-11-01
影响因子：
2.8
通讯作者：
Li, Yunpeng
中科院分区：
文献类型：
--
作者：
Jiang, Hongkun;Li, Lei;Li, Yunpeng
肾脏异常常见于TBX 1基因缺失的患者，该基因编码与许多发育过程有关的重要转录因子。Pax 2是同源异型基因的“配对盒”（PAX）家族的成员，其在肾发生期间协调特定细胞中的基因表达模式。在本研究中，我们假设Pax 2可能激活与肾脏发育密切相关的T-box家族成员TBX 1的表达。采用免疫组织化学和免疫荧光法检测TBX 1在E16. 5胎鼠肾脏中的表达，荧光素酶法、电泳迁移率变动分析（EMSA）和染色质免疫沉淀（ChIP）法检测Pax 2蛋白与TBX 1基因的相互作用。TBX 1在E16.5胎鼠肾皮质肾小管上皮细胞胞浆中表达。TBX 1基因的50-侧翼序列的检查确定了一个推定的Pax 2识别基序（TBX 1 -577）。荧光素酶分析和EMSA证实了这一新的TBX 1启动子区域与Pax 2直接相互作用，并且位点突变可以消除Pax 2对TBX 1启动子的转录激活作用。ChIP检测人肾上皮细胞Pax 2-TBX 1启动子复合物进一步证实了内源性Pax 2与TBX 1启动子区相互作用。因此，Pax 2直接调节TBX 1在体内的表达。这些结果提示Pax 2可能通过与TBX 1启动子特异性结合来调控TBX 1的表达，这可能揭示Pax 2和TBX 1在肾发生和肾畸形中的潜在机制。
Renal anomaly is commonly found among patients with loss of TBX1 gene, encoding an important transcriptional factor implicated in numerous developmental processes. Pax2 is a member of the "paired-box" (PAX) family of homeotic genes that orchestrates the patterns of gene expression in specific cells during nephrogenesis. In this study, we hypothesized that Pax2 might activate expression of TBX1, a member of T-box family that closely involving in kidney development. Immunohistochemical and immunofluorescence staining was performed to detect TBX1 expression in E16.5 embryonic rat kidney, while luciferase assay, electrophoretic mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP) assay were used to confirm the interaction between the Pax2 protein and TBX1 genes. TBX1 was expressed in the cytoplasm of renal tubular epithelial cells in the cortex of E16.5 fetal rat kidney. Inspection of the 50-flanking sequence of the TBX1 gene identified a putative Pax2 recognition motif (TBX1-577). Luciferase assay and EMSA confirmed this novel promoter region of TBX1 that directly interacted with Pax2, and a site mutation could abolish the transcriptional activation of the TBX1 promoter by Pax2. ChIP assay of the Pax2-TBX1 promoter complex from human kidney epithelial cells further confirmed that endogenous Pax2 interacted with TBX1 promoter region. Thus, Pax2 directly regulates TBX1 expression in vivo. These findings suggest that Pax2 may regulate the TBX1 expression through specific binding to the TBX1 promoter, which may shed light on the potential mechanism of Pax2 and TBX1 in nephrogenesis and renal malformations.