Transcriptional control of endothelium in APS by Kruppel Like factors

 描述（由申请方提供）：抗磷脂抗体（APLA）与动脉和静脉血栓形成相关，是主要心血管发病率和死亡率的原因。患有APL相关血栓形成的个体接受终身抗凝治疗。APLA的主要抗原不是磷脂，而是β2-糖蛋白I（β2GPI），一种丰富的磷脂结合糖蛋白。与抗β2GPI抗体相关的血栓前状态可能是由于其以β 2GPI依赖性方式激活血管内皮细胞（EC）的能力所致。我们已经证明APLA激活EC受Krüppel样转录因子（KLF），特别是KLF 2和4的调节。本申请的目的是确定EC KLF调节对APLA的血栓前反应的机制。为了实现这一点，我们将使用新的动物模型，其中KLF的表达已经以全局或细胞特异性方式改变。在具体目标1中，我们将评估APLA诱导从缺乏KLF 2和/或KLF 4的小鼠中分离的EC活化的能力，并确定KLF 2/4如何影响内皮转录组对APLA的反应。这些研究将结合评估KLF 2/4调节小鼠中APL介导的动脉、小动脉和小静脉血栓形成的能力。在具体目标2中，我们将确定他汀类药物阻断APL介导的EC活化的能力是否具有KLF依赖性。他汀类药物对APL激活EC的转录组的影响也将与在不存在他汀类药物的情况下观察到的影响进行比较。最后，APLA通过TLR 4-NFκB通路激活EC，我们已经证明KLF 2/4阻断APLA激活EC的能力反映了NFκB辅激活因子CBP/p300的隔离作用;然而，NFκB的其他转录辅激活因子和辅抑制因子的作用尚不清楚。在具体目标3中，我们将评估APLA对NFκB转录复合物组装的影响，包括共激活因子（p300/PCAF）和共抑制因子（NCoR/SMRT/HDAC）;我们还将确定他汀类药物是否以KLF依赖性方式抑制该复合物的组装。这些研究将提供有关KLF调节APL诱导的EC激活和血栓形成的明确信息，并提供针对性干预措施以预防APS的破坏性后果。

 DESCRIPTION (provided by applicant): Antiphospholipid antibodies (APLA) are associated with arterial and venous thrombosis, and are a cause of major cardiovascular morbidity and mortality. Individuals with APLA-associated thrombosis are treated with lifelong anticoagulation. The primary antigen for APLA is not phospholipid, but β2-glycoprotein I (β2GPI), an abundant phospholipid-binding glycoprotein. The prothrombotic state associated with anti-β2GPI antibodies may result from their ability to activate vascular endothelial cells (EC) in a β2GPI-dependent manner. We have demonstrated that activation of EC by APLA is regulated by Krüppel-like transcription factors (KLFs), particularly KLF2 and 4. The goal of this application i to define the mechanisms by which EC KLFs regulate the prothrombotic response to APLA. To accomplish this, we will use novel animal models in which the expression of KLFs has been altered in a global or cell-specific manner. In Specific Aim 1, we will assess the ability of APLA to induce activation of EC isolated from mice lacking KLF2 and/or KLF4, and determine how KLF2/4 affect the endothelial transcriptome in response to APLA. These studies will be coupled to assessment of the ability of KLF2/4 to modulate APLA-mediated arterial, arteriolar, and venular thrombosis in mice. In Specific Aim 2, we will determine whether the ability of statins to block APLA-mediated EC activation are KLF- dependent. The effects of statins on the transcriptome of APLA-activated EC will also be compared to that observed in the absence of statins. Finally, APLA activate EC through a TLR4-NFκB pathway, and we have demonstrated that the ability of KLF2/4 to block EC activation by APLA reflects sequestration of the NFκB coactivator CBP/p300; however, the role of other transcriptional co-activators and co-repressors of NFκB is unknown. In Specific Aim 3, we will assess the effects of APLA on assembly of the NFκB transcriptional complex, including co-activators (p300/PCAF) and co-repressors (NCoR/SMRT/HDACs); we will also determine whether statins inhibit assembly of this complex in a KLF-dependent manner. These studies will provide definitive information on the regulation of APLA-induced EC activation and thrombosis by KLFs, and provide insight into targeted interventions to prevent the devastating consequences of APS.