Hyaluronan Export through Plasma Membranes Depends on Concurrent K+ Efflux by Kir Channels
Hyaluronan Export through Plasma Membranes Depends on Concurrent K+ Efflux by Kir Channels
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DOI：
10.1371/journal.pone.0039096
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发表时间：
2012-06-11
期刊：
影响因子：
3.7
通讯作者：
Prehm, Peter
中科院分区：
文献类型：
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作者：
Hagenfeld, Daniel;Borkenhagen, Beatrice;Prehm, Peter
透明质酸是在细胞质内合成的，并由MRP5转运蛋白通过成纤维细胞的细胞膜输出到细胞外基质中。为了满足电中性定律，需要一个阳离子来中和出现的透明质酸负电荷。正如我们以前观察到的K+通道抑制剂对透明质酸输出的抑制一样，现在通过在药物存在的情况下同时测量膜电位来分析透明质酸输出。这是通过将透明质酸导入到由内向外的囊泡中和通过反义siRNA抑制来实现的。格列本脲、罗比卡因和BaCl2都是ATP敏感的内向整流性K-ir通道抑制剂，对成纤维细胞透明质酸的输出有明显的抑制作用。150 mM KCl可激活透明质酸进入囊泡，而这种激活可被ATP取消。K+通道K(Ir)3.4和K(Ir)6.2的siRNA抑制透明质酸输出。综上所述，这些结果表明透明质酸的输出依赖于并发的K+外流。
Hyaluronan is synthesized within the cytoplasm and exported into the extracellular matrix through the cell membrane of fibroblasts by the MRP5 transporter. In order to meet the law of electroneutrality, a cation is required to neutralize the emerging negative hyaluronan charges. As we previously observed an inhibiting of hyaluronan export by inhibitors of K+ channels, hyaluronan export was now analysed by simultaneously measuring membrane potential in the presence of drugs. This was done by both hyaluronan import into inside-out vesicles and by inhibition with antisense siRNA. Hyaluronan export from fibroblast was particularly inhibited by glibenclamide, ropivacain and BaCl2 which all belong to ATP-sensitive inwardly-rectifying K-ir channel inhibitors. Import of hyaluronan into vesicles was activated by 150 mM KCl and this activation was abolished by ATP. siRNA for the K+ channels K(ir)3.4 and K(ir)6.2 inhibited hyaluronan export. Collectively, these results indicated that hyaluronan export depends on concurrent K+ efflux.