Natriuretic peptides up-regulate aquaporin 3 in a human colonic epithelial cell line.
Natriuretic peptides up-regulate aquaporin 3 in a human colonic epithelial cell line.
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DOI：
10.3892/ijmm.14.4.621
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发表时间：
2004-10
影响因子：
5.4
通讯作者：
A. Itoh;T. Tsujikawa;T. Yasuoka;T. Nakahara;M. Sasaki;Y. Fujiyama
中科院分区：
文献类型：
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作者：
A. Itoh;T. Tsujikawa;T. Yasuoka;T. Nakahara;M. Sasaki;Y. Fujiyama
有几个称为水通道蛋白(AQP)的特殊通道促进了胃肠道中的水运输。AQP3定位于人小肠和结肠的上皮细胞。然而，对AQP3在胃肠道中功能的调节机制还不是很清楚。为了研究心钠素(ANP)和脑利钠肽(BNP)对AQP3表达的调节作用，我们用Northern印迹法检测了人结肠上皮细胞株HT-29中AQP3基因的表达，用Western blotting法检测了蛋白的表达，用凝胶迁移率改变分析法(EMSA)研究了DNA结合活性。我们还使用了几种抑制剂来研究信号转导。除ANP(>；100 nM)和BNP(>；10 nM)外，AQP3的mRNA表达上调。加入ANP和BNP后1h，AQP3蛋白表达增强。蛋白激酶-A(PK-A)和蛋白激酶-G(PK-G)抑制剂联合应用可完全抑制ANP或BNP诱导的AQP3mRNA表达，使其达到基础水平。HT-29细胞的环磷酸腺苷反应元件(CRE)的EMSA显示单一条带。这些结果表明，ANP和BNP上调AQP3mRNA和蛋白的表达，PK-A和PK-G依赖的通路都介导了这一作用。
Several specialized channels termed aquaporins (AQPs) facilitate water transport in the gastrointestinal tract. AQP3 localizes to epithelial cells in the human small intestine and colon. However, the regulatory mechanisms responsible for AQP3 function in the gastrointestinal tract are not well understood. To characterize the regulation of AQP3 expression by atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), we studied mRNA expression by Northern blotting, protein expression by Western blotting and DNA binding activity by electrophoretic mobility shift assay (EMSA) in the human colonic epithelial cell line HT-29. We also used several inhibitors to investigate signal transduction. AQP3 mRNA was up-regulated in addition to ANP (>100 nM) and BNP (>10 nM). The expression of AQP3 protein was enhanced at 1 h after the addition of ANP and BNP. The combination of protein kinase-A (PK-A) and protein kinase-G (PK-G) inhibitors completely inhibited the expression of AQP3 mRNA enhanced by ANP or BNP to its basal level. The EMSA of the cyclic-AMP response element (CRE) in HT-29 cells revealed a single band. These results indicate that ANP and BNP up-regulated the expression of AQP3 mRNA and protein, and both PK-A and PK-G dependent pathways mediated this effect.