Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada.
Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Canada.
J Leukoc Biol. 2018 Jul;104(1):147-158. doi: 10.1002/JLB.3MA1117-429R. Epub 2018 Apr 6.
Leukocyte recruitment plays a critical role during both normal inflammation and chronic inflammatory diseases, and ongoing studies endeavor to better understand the complexities of this process. Focal adhesion kinase (FAK) is well known for its role in cancer, yet it also has been shown to regulate aspects of neutrophil and B16 melanoma cell recruitment by rapidly influencing endothelial cell focal adhesion dynamics and junctional opening. Recently, we found that FAK related non-kinase (FRNK), a protein that is often used as a FAK dominant negative, blocked eosinophil transmigration by preventing the transcription of vascular cell adhesion molecule-1 (VCAM-1) and eotaxin-3 (CCL26). Surprisingly, the blocking occurred even in the absence of endogenous FAK. To better understand the role of FAK in leukocyte recruitment, we used a FAK-specific inhibitor (PF-573228) and determined the effect on IL-4 induced eosinophil recruitment in vitro and in vivo. PF-573228 prevented the expression of VCAM-1 and CCL26 expression in IL-4-stimulated human endothelial cells in vitro. As a result, eosinophil adhesion and transmigration were blocked. PF-572338 also prevented IL-4-induced VCAM-1 expression in vivo. Using brightfield intravital microscopy, we found that PF-573228 decreased leukocyte rolling flux, adhesion, and emigration. We specifically examined eosinophil recruitment in vivo by using an eosinophil-GFP reporter mouse and found PF-573228 attenuated eosinophil emigration. This study reveals that a FAK inhibitor influences inflammation through its action on eosinophil recruitment.
白细胞募集在正常炎症和慢性炎症性疾病中都起着关键作用，目前的研究旨在更好地了解这一过程的复杂性。黏着斑激酶 (FAK) 以其在癌症中的作用而闻名，但它也被证明可以通过快速影响内皮细胞黏附斑动力学和连接打开来调节中性粒细胞和 B16 黑色素瘤细胞募集的各个方面。最近，我们发现 FAK 相关非激酶 (FRNK)，一种常被用作 FAK 显性失活的蛋白，通过阻止血管细胞黏附分子-1 (VCAM-1) 和嗜酸性粒细胞趋化因子-3 (CCL26) 的转录，阻止嗜酸性粒细胞迁移。令人惊讶的是，即使在没有内源性 FAK 的情况下，这种阻断也会发生。为了更好地了解 FAK 在白细胞募集中的作用，我们使用了一种 FAK 特异性抑制剂 (PF-573228)，并确定了其对体外和体内白细胞介素-4 诱导的嗜酸性粒细胞募集的影响。PF-573228 阻止了 VCAM-1 和 CCL26 在体外白细胞介素-4 刺激的人内皮细胞中的表达。结果，嗜酸性粒细胞黏附和迁移被阻断。PF-572338 也阻止了体内白细胞介素-4 诱导的 VCAM-1 表达。使用明场活体显微镜，我们发现 PF-573228 降低了白细胞滚动通量、黏附和迁移。我们专门使用嗜酸性粒细胞-GFP 报告小鼠研究了体内嗜酸性粒细胞募集，发现 PF-573228 减弱了嗜酸性粒细胞迁移。这项研究揭示了 FAK 抑制剂通过影响嗜酸性粒细胞募集来影响炎症。
