Globotriaosylceramide Induces Lysosomal Degradation of Endothelial KCa3.1 in Fabry Disease
Globotriaosylceramide Induces Lysosomal Degradation of Endothelial KCa3.1 in Fabry Disease
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DOI：
10.1161/atvbaha.113.302200
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发表时间：
2014-01-01
影响因子：
8.7
通讯作者：
Suh, Suk Hyo
中科院分区：
文献类型：
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作者：
Choi, Shinkyu;Kim, Ji Aee;Suh, Suk Hyo
目的：globotriaosylceramide （Gb3）诱导Fabry病（FD）患者K(Ca)3.1下调。我们研究了Gb3是否诱导K(Ca)3.1的内吞和降解。方法与结果-在gb3处理的小鼠主动脉内皮细胞（MAECs）和人脐静脉内皮细胞中，K(Ca)3.1，尤其是质膜定位的K(Ca)3.1均下调。溶酶体抑制剂可阻止gb3诱导的K(Ca)3.1下调，而蛋白体抑制剂则不能。内质网应激诱导剂不诱导K(Ca)3.1下调。Gb3上调MAECs早期内体抗原1和溶酶体相关膜蛋白2的蛋白水平。与年龄匹配野生型小鼠的MAECs相比，老年α -半乳糖苷酶A （Gla）敲除小鼠（FD动物模型）的MAECs显示K(Ca)3.1表达下调，早期内体抗原1和溶酶体相关膜蛋白2表达上调。相比之下，在早期内体抗原1和溶酶体相关膜蛋白2的表达在年轻的玻璃敲除型和野生型maec之间没有显著差异。在衰老的玻璃敲除maec中，网格蛋白在靠近细胞边界的地方易位，网格蛋白敲除恢复了K(Ca)3.1的表达。早期内体抗原1的效应物Rab5上调，Rab5敲低恢复K(Ca)3.1的表达、电流和内皮依赖性松弛。结论- gb3通过网格蛋白依赖的过程加速内皮细胞K(Ca)3.1的内吞作用和溶酶体降解，导致FD的内皮功能障碍。
Objective-Globotriaosylceramide (Gb3) induces K(Ca)3.1 downregulation in Fabry disease (FD). We investigated whether Gb3 induces K(Ca)3.1 endocytosis and degradation.Approach and Results-K(Ca)3.1, especially plasma membrane-localized K(Ca)3.1, was downregulated in both Gb3-treated mouse aortic endothelial cells (MAECs) and human umbilical vein endothelial cells. Gb3-induced K(Ca)3.1 downregulation was prevented by lysosomal inhibitors but not by a proteosomal inhibitor. Endoplasmic reticulum stress-inducing agents did not induce K(Ca)3.1 downregulation. Gb3 upregulated the protein levels of early endosome antigen 1 and lysosomal-associated membrane protein 2 in MAECs. Compared with MAECs from age-matched wild-type mice, those from aged alpha-galactosidase A (Gla)-knockout mice, an animal model of FD, showed downregulated K(Ca)3.1 expression and upregulated early endosome antigen 1 and lysosomal-associated membrane protein 2 expression. In contrast, no significant difference was found in early endosome antigen 1 and lysosomal-associated membrane protein 2 expression between young Gla-knockout and wild-type MAECs. In aged Gla-knockout MAECs, clathrin was translocated close to the cell border and clathrin knockdown recovered K(Ca)3.1 expression. Rab5, an effector of early endosome antigen 1, was upregulated, and Rab5 knockdown restored K(Ca)3.1 expression, the current, and endothelium-dependent relaxation.Conclusions-Gb3 accelerates the endocytosis and lysosomal degradation of endothelial K(Ca)3.1 via a clathrin-dependent process, leading to endothelial dysfunction in FD.