Knowles Lynn M, Ampofo Emmanuel, Menger Michael D, Drawz Anna, Eichler Hermann, Pilch Jan
Institute of Clinical Hemostaseology and Transfusion Medicine, Saarland University and University Medical Center, Homburg, Germany.
Institute for Clinical and Experimental Surgery, Saarland University and University Medical Center, Homburg, Germany.
Transfus Med Hemother. 2025 Feb 12;52(3):178-189. doi: 10.1159/000544115. eCollection 2025 Jun.
Chloride intracellular channel 1 (CLIC1) is expressed in endothelial cells and platelets. Loss-of-function studies suggest that CLIC1 is involved in adhesive interactions in either cell type, but the exact mechanism of CLIC1 action is still a matter of debate.
Cultured endothelial cells and platelets were probed for CLIC1 function as well as subcellular location using fluorescence microscopy, flow cytometry, and light transmission aggregometry. CLIC1 function in vivo was tested using a mouse dorsal skin fold chamber model to assess thrombus formation.
Knocking down CLIC1 in endothelial cells is associated with the inability of cells to spread after attachment to the extracellular matrix. Critical to this process is the endothelial integrin αvβ3, which mediates the recruitment of CLIC1 into newly formed lamellipodia and subsequent colocalization with F-actin. Inhibiting CLIC1 with siRNA or the synthetic CLIC1 inhibitor IAA94, on the other hand, reduced F-actin formation in nascent adhesions, indicating that CLIC1 supports integrin β3-mediated cytoskeletal dynamics during endothelial cell attachment. In addition to endothelial cells, colocalization of CLIC1 with F-actin was detected in lamellipodia of platelets, which relocate CLIC1 to their cell surface in an integrin-dependent manner. Treatment with the CLIC1 inhibitor IAA94 hindered CLIC1 relocation to the platelet membrane, diminished platelet aggregation, and reduced integrin αβ activation. Injecting mice with IAA94 delayed vaso-occlusion in a mouse model of photochemical thrombus formation in vivo.
CLIC1 is regulated by adhesive interactions with integrin ligands that cause CLIC1 to relocate to the cell membrane of endothelial cells and platelets. This process in turn appears to be relevant for integrin-mediated functions involved in platelet thrombus formation in vitro and in vivo.
氯离子细胞内通道1（CLIC1）在内皮细胞和血小板中表达。功能丧失研究表明，CLIC1参与这两种细胞类型的黏附相互作用，但CLIC1作用的确切机制仍存在争议。
使用荧光显微镜、流式细胞术和光透射聚集测定法检测培养的内皮细胞和血小板的CLIC1功能以及亚细胞定位。使用小鼠背部皮肤褶皱腔室模型评估血栓形成，以测试CLIC1在体内的功能。
在内皮细胞中敲低CLIC1与细胞附着于细胞外基质后无法铺展有关。这一过程的关键是内皮整合素αvβ3，它介导CLIC1募集到新形成的片状伪足中，并随后与F-肌动蛋白共定位。另一方面，用小干扰RNA（siRNA）或合成的CLIC1抑制剂IAA94抑制CLIC1，可减少新生黏附中F-肌动蛋白的形成，表明CLIC1在内皮细胞附着过程中支持整合素β3介导的细胞骨架动力学。除内皮细胞外，在血小板的片状伪足中检测到CLIC1与F-肌动蛋白共定位，血小板以整合素依赖性方式将CLIC1重新定位到其细胞表面。用CLIC1抑制剂IAA94处理会阻碍CLIC1重新定位到血小板膜，减少血小板聚集，并降低整合素αβ活化。在体内光化学血栓形成小鼠模型中给小鼠注射IAA94可延迟血管闭塞。
CLIC1受与整合素配体的黏附相互作用调节，这种相互作用导致CLIC1重新定位到内皮细胞和血小板的细胞膜。这一过程反过来似乎与体外和体内血小板血栓形成中涉及的整合素介导的功能相关。
