MacKay Charles E, Floen Miranda, Leo M Dennis, Hasan Raquibul, Garrud Tessa A C, Fernández-Peña Carlos, Singh Purnima, Malik Kafait U, Jaggar Jonathan H
Department of Physiology, University of Tennessee Health Science Center, Memphis, United States.
Elife. 2022 Mar 1;11:e74765. doi: 10.7554/eLife.74765.
Polycystin-1 (PC-1, PKD1), a receptor-like protein expressed by the gene, is present in a wide variety of cell types, but its cellular location, signaling mechanisms, and physiological functions are poorly understood. Here, by studying tamoxifen-inducible, endothelial cell (EC)-specific knockout ( ecKO) mice, we show that flow activates PC-1-mediated, Ca-dependent cation currents in ECs. EC-specific PC-1 knockout attenuates flow-mediated arterial hyperpolarization and vasodilation. PC-1-dependent vasodilation occurs over the entire functional shear stress range and via the activation of endothelial nitric oxide synthase (eNOS) and intermediate (IK)- and small (SK)-conductance Ca-activated K channels. EC-specific PC-1 knockout increases systemic blood pressure without altering kidney anatomy. PC-1 coimmunoprecipitates with polycystin-2 (PC-2, PKD2), a TRP polycystin channel, and clusters of both proteins locate in nanoscale proximity in the EC plasma membrane. Knockout of either PC-1 or PC-2 ( ecKO mice) abolishes surface clusters of both PC-1 and PC-2 in ECs. Single knockout of PC-1 or PC-2 or double knockout of PC-1 and PC-2 (/ ecKO mice) similarly attenuates flow-mediated vasodilation. Flow stimulates nonselective cation currents in ECs that are similarly inhibited by either PC-1 or PC-2 knockout or by interference peptides corresponding to the C-terminus coiled-coil domains present in PC-1 or PC-2. In summary, we show that PC-1 regulates arterial contractility through the formation of an interdependent signaling complex with PC-2 in ECs. Flow stimulates PC-1/PC-2 clusters in the EC plasma membrane, leading to eNOS, IK channel, and SK channel activation, vasodilation, and a reduction in blood pressure.
多囊蛋白-1（PC-1，PKD1）是一种由该基因表达的受体样蛋白，存在于多种细胞类型中，但其细胞定位、信号传导机制和生理功能仍知之甚少。在这里，通过研究他莫昔芬诱导的内皮细胞（EC）特异性敲除（ecKO）小鼠，我们发现血流可激活内皮细胞中PC-1介导的、钙依赖性阳离子电流。内皮细胞特异性PC-1敲除减弱了血流介导的动脉超极化和血管舒张。PC-1依赖性血管舒张在整个功能性剪切应力范围内发生，并通过激活内皮型一氧化氮合酶（eNOS）以及中间（IK）和小（SK）电导的钙激活钾通道来实现。内皮细胞特异性PC-1敲除会升高全身血压，而不会改变肾脏解剖结构。PC-1与TRP多囊蛋白通道多囊蛋白-2（PC-2，PKD2）共免疫沉淀，并且这两种蛋白的簇在EC质膜中以纳米级的距离定位。敲除PC-1或PC-2（ecKO小鼠）会消除EC中PC-1和PC-2的表面簇。单独敲除PC-1或PC-2或同时敲除PC-1和PC-2（/ecKO小鼠）同样会减弱血流介导的血管舒张。血流刺激内皮细胞中的非选择性阳离子电流，PC-1或PC-2敲除或与PC-1或PC-2中存在的C末端卷曲螺旋结构域对应的干扰肽同样会抑制这种电流。总之，我们表明PC-1通过在EC中与PC-2形成相互依赖的信号复合物来调节动脉收缩性。血流刺激EC质膜中的PC-1/PC-2簇，导致eNOS、IK通道和SK通道激活、血管舒张以及血压降低。
