The role of Ca(2+) sensitive tyrosine kinase PYK2 as a molecule to transmit cardiovascular stresses

动脉粥样硬化是由内皮细胞（EC）功能障碍引发的炎症过程，其中细胞内活性氧（ROS）起着至关重要的作用。控制动脉粥样硬化的治疗方法尚未得到充分发展。氧化还原敏感酪氨酸激酶PYK2已被证明可促进炎症。我们在这里首次发现，高胆固醇饮食后7天，ROS/p21介导的过早衰老和p21相关炎症分子的合成在内皮细胞中被诱导，PYK2缺乏时，这些事件和最终的动脉粥样硬化被显著抑制。方法：将PYK2缺陷小鼠（PYK2- ko）与ApoE缺陷小鼠（ApoE- ko）杂交，建立PYK2/ApoE双缺陷小鼠（PYK2/ApoE- d - ko）。4周大的小鼠喂食高胆固醇饮食8周。结果：PYK2/ApoE-D-KO组胸主动脉动脉粥样硬化面积减小至ApoE-KO的55% （p<0.01）。骨髓替代实验表明，血管壁和造血细胞中PYK2的缺乏同样有助于这种减少。在饲喂后第7天进行进一步分析。饲粮后第7天，PYK2/ApoE-D-KO组胸主动脉内皮中VCAM1、MCP-1、LOX-1和ROS的合成分别比ApoE-KO组低48%、31%、78%和74% （p<0.05）。PYK2通过上调VAV2/Racl激活NADPH氧化酶。第7天，ApoE- ko -小鼠主动脉内皮中p21蛋白的表达和衰老相关的-□-gal活性升高，而nadph抑制剂降低了p21蛋白的表达，而ApoE/PYK2-D-KO小鼠的p21蛋白水平升高被消除。用p21-siRNA处理培养的WT-ECs可降低VCAM-1、MCP-1和LOX-1的表达。ros依赖性转录因子Ets-1在PYK2-KO-ECs中的表达明显降低，其敲除消除了WT-ECs中的分子诱导作用。结论：PYK2通过ROS/p21介导的内皮细胞过早衰老启动动脉粥样硬化。因此，PYK2是控制动脉粥样硬化发展的潜在治疗靶点。少

Atherosclerosis is an inflammatory process initiated by endothelial cell (EC) dysfunction in which intracellular reactive oxygen species (ROS) plays crucial role. The therapy to control atherosclerosis has not been fully developed. Redox sensitive tyrosine kinase, PYK2 has been shown to promote inflammation. We here show for the first time that ROS/p21-mediated premature senescence and p21-related synthesis of inflammatory molecules was induced in endothelium just at 7 days after high cholesterol diet and in PYK2 deficiency, these events and eventual atherosclerosis were markedly inhibited. Methods: PYK2 deficient mice (PYK2-KO) were crossbred with ApoE deficient mice (ApoE-KO) and PYK2/ApoE double deficient mice (PYK2/ApoE-D-KO) were established. Four-week-old mice were fed with high-cholesterol-diet for 8 weeks. Results: Atherosclerotic area in the thoracic aorta of PYK2/ApoE-D-KO decreased to 55% of ApoE-KO (p<0.01). Bone marrow replacement experiment revealed that PYK2 deficiency i … More n the vascular wall and in the hematopoietic cells similarly contributes to this reduction. Further analysis was performed at day 7 after diet. Syntheses of VCAM1, MCP-1, LOX-1 and ROS in the endothelium of the thoracic aorta of PYK2/ApoE-D-KO were 48%, 31%, 78% and 74% lower than ApoE-KO (each p<0.05) at 7 days after diet. PYK2 activated NADPH oxidase through upregulation of VAV2/Racl. Expression of p21 protein and senescence associated-□-gal-activity in endothelium of aorta increased in ApoE-KO-mice at day 7, whereas treatment with NADPH-inhibitor decreased p21 protein level and this increase in p21 protein level were abolished in ApoE/PYK2-D-KO mice. Treatment with p21-siRNA in cultured WT-ECs reduced expression of VCAM-1, MCP-1 and LOX-1. Expression of ROS-dependent transcription factor, Ets-1, markedly decreased in PYK2-KO-ECs and its knockdown abolished molecular induction in WT-ECs. Conclusion: PYK2 initiate atherosclerosis through ROS/p21-mediated endothelial premature senescence. Thus, PYK2 is a potential therapeutic target to control development of atherosclerosis. Less