The Matricellular Protein Cyr61 Signaling Axis in Arterial Restenosis

血管平滑肌细胞(SMC)迁移是动脉再狭窄重塑的关键事件 在血管成形术和支架植入之后。尽管最近药物洗脱技术取得了进步，但动脉再狭窄 仍然是一个具有挑战性的复杂问题。为了开发创新的治疗方法，发现新的 再狭窄的调控分子和机制是必要的。大量证据表明，血小板- 衍生生长因子(PDGF)在血管损伤后SMC向内膜迁移中起重要作用。 我们最近发表的文章揭示了新生的基质细胞蛋白Cyr61(CCN1)是介导 血小板衍生生长因子通过与整合素α-6-β-1的相互作用，通过“由外而内”的信号通路诱导系膜细胞迁移 和αvβ3，导致细胞内粘着斑激酶的激活。这表明存在Cyr61信号 动脉再狭窄的轴心。有趣的是，我们最近也观察到了小鼠高水平的Cyr61表达 血管成形术导丝引起的股动脉病变。追求的作用和新颖的信号组件 在动脉再狭窄的Cyr61轴上，我们探索了极化导联中一系列蛋白激酶的激活。 使用一种新的伪足分离方法对SMC的边缘进行分离。令人兴奋的是，我们的初步数据显示 以下发现：PDGF诱导一种新的伪足丰富的非典型激酶1(PEAK1)的激活， 定位于SMC极化前沿；Cyr61基因敲除阻断PDGF诱导的PEAK1 激活PEAK1阻断PDGF诱导的SMC迁移和PDGF诱导的磷酸化 PEAK1(p-PEAK1)在SMC中与p-FAK相互作用。重要的是，我们观察到Cyr61水平和PEAK1 在导丝诱导的小鼠股动脉损伤中，激活被强烈地诱导。此外，两个Cyr61 P-PEAK1定位于病变的SMC，但不定位于中膜SMC。这些数据强烈地表明，Cyr61 而新的伪足蛋白激酶PEAK1在损伤诱导的动脉再狭窄中起着关键作用。基于 这些新的观察结果，我们假设Cyr61-α6β1/αvβ3-p-PEAK1-p-FAK介导了损伤诱导 SMC迁移和Cyr61和p-PEAK1控制动脉再狭窄的血管重构。我们的假设 将在以下具体目标中进行测试。目的1：确定PDGF中p-PEAK1与p-FAK的相互作用 途径，确定作为治疗靶点的抑制性多肽，并研究Cyr61在 使用我们最近创建的SMC特异性的新型Cyr61缺失的SMC激活细胞内级联 Cyr61KO小鼠。目的2：探讨α-6-β-1和α-v-β-3在血小板衍生生长因子诱导下可能形成的复合体 Cyr61途径，并利用来源的SMCs确定细胞内分子的后续激活 来自创新的Cyr61dm/dm、Cyr61D125A和SMC特定的Cyr61-/-小鼠。目标3：确定Cyr61的作用 和新的酪氨酸激酶PEAK1在血管成形术诱导的血管重塑中使用三个创新的Cyr61 遗传模型Cyr61dm/dm、Cyr61D125A和SMC Cyr61 KO小鼠。拟议的研究预计将确定 防治动脉再狭窄的新靶点。

Vascular smooth muscle cell (SMC) migration is a critical event in the arterial remodeling in restenosis following angioplasty and stenting. Despite recent advances in drug-eluting technology, arterial restenosis remains a challenging complication. In order to develop innovative therapeutic approaches, discovery of novel regulatory molecules and mechanisms of restenosis is needed. Substantial evidence has shown that platelet- derived growth factor (PDGF) plays a prominent role in SMC migration into the intima following vascular injury. Our recent publication revealed that de novo matricellular protein Cyr61 (CCN1) is the key molecule mediating the PDGF-induced SMC migration via an “outside-in” signaling route through its interaction with integrins α6β1 and αvβ3, which leads to intracellular focal adhesion kinase (FAK) activation. This suggests a Cyr61 signaling axis in arterial restenosis. Interestingly, we also recently observed high levels of Cyr61 expression in mouse angioplasty guidewire-induced femoral arterial lesions. To pursue the role and novel signaling components of the Cyr61 axis in arterial restenosis, we explored an array of protein kinase activation in the polarized leading edge of SMCs using a novel pseudopodium isolation approach. Excitingly, our preliminary data revealed the following findings: PDGF induces activation of a novel pseudopodium-enriched atypical kinase 1 (PEAK1), which is localized in the polarized leading edge of SMCs; knockdown of Cyr61 blocks PDGF-induced PEAK1 activation; depletion of PEAK1 blocks PDGF-induced SMC migration; and PDGF-induced phosphorylated PEAK1 (p-PEAK1) interacts with p-FAK in SMCs. Importantly, we observed that Cyr61 levels and PEAK1 activation are robustly induced in guidewire-induced mouse femoral arterial lesions. Furthermore, both Cyr61 and p-PEAK1 localize in lesion SMCs but not in tunica media SMCs. These data strongly suggest that Cyr61 and the novel pseudopodium kinase PEAK1 play crucial roles in injury-induced arterial restenosis. Based on these new observations, we hypothesize that the Cyr61-α6β1/αvβ3-p-PEAK1-p-FAK mediates injury-induced SMC migration and that Cyr61 and p-PEAK1 control vascular remodeling in arterial restenosis. Our hypothesis will be tested in the following specific aims. Aim 1: Determine how p-PEAK1 interacts with p-FAK in the PDGF pathway, identify the inhibitory peptides serving as therapeutic targets, and examine the key role of Cyr61 on the activation of intracellular cascades using novel Cyr61 null SMCs from our recently created SMC-specific Cyr61 KO mice. Aim 2: Explore the possible complex formation between α6β1 and αvβ3 in PDGF-induced Cyr61 pathway and determine the consequent activation of the intracellular molecules using SMCs derived from innovative Cyr61dm/dm, Cyr61D125A, and SMC-specific Cyr61-/- mice. Aim 3: Determine the role of Cyr61 and novel tyrosine kinase PEAK1 in angioplasty-induced vascular remodeling using three innovative Cyr61 genetic models Cyr61dm/dm, Cyr61D125A, and SMC Cyr61 KO mice. The proposed studies are expected to identify novel targets for prevention and treatment of arterial restenosis.