Transcriptional control of endothelium in APS by Kruppel Like factors

 描述(申请人提供)：抗磷脂抗体(APLA)与动脉和静脉血栓形成有关，是导致主要心血管疾病和死亡的原因。患有APLA相关血栓的患者要接受终身抗凝治疗。APLA的主要抗原不是磷脂，而是β2-糖蛋白I(β2GPI)，它是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源于它们以β2GPI依赖的方式激活血管内皮细胞(EC)的能力。我们已经证明，APLA对EC的激活是由Krüppel样转录因子(KLF)调节的，特别是KLF2和KLF4。本申请的目的是定义EC KLF调节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，在这些模型中，KLFS的表达已经以全局或细胞特异性的方式改变。在特定的目标1中，我们将评估APLA诱导从缺乏KLF2和/或KLF4的小鼠分离的EC激活的能力，并确定KLF2/4如何影响APLA对内皮转录组的反应。这些研究将与评估KLF2/4调节APLA介导的小鼠动脉、小动脉和小静脉血栓形成的能力相结合。在特定的目标2中，我们将确定他汀类药物阻断APLA介导的EC激活的能力是否依赖于KLF。他汀类药物对APLA激活的EC转录组的影响也将与没有他汀类药物时观察到的效果进行比较。最后，APLA通过TLR4-NFκB途径激活EC，我们已经证明KLF2/4阻断APLA激活EC的能力反映了NFκB辅助激活因子CBP/p300的隔离；然而，其他转录辅助激活因子和辅助抑制因子的作用尚不清楚。在特定的目标3，我们将评估APLA对NFκB转录复合体组装的影响，包括共激活子(p300/PCAF)和共抑制子(NCoR/SMRT/HDAC)；我们还将确定他汀类药物是否以KLf依赖的方式抑制该复合体的组装。这些研究将为KLF对APLA诱导的EC激活和血栓形成的调控提供明确的信息，并为预防APS的破坏性后果提供有针对性的干预措施。

 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.