炎症共刺激分子CD137-CD137L调控NFATc1启动粥样斑块钙化的机制

Vascular calcification is the main cause of myocardial infarction and vascular dissection, as it can easily result in plaque rupture, especially the microcalcifications in the plaques. It has been prompted that nuclear factor of activated T cells 1 (NFATc1) plays a role as a molecular switch for the regulation of vascular calcification. Our previous studies have demonstrated that NFATc1 is the downstream molecule of CD137-CD137L interaction for the regulation of the development of plaque progression in ApoE-/- mice. In vivo, the expression of NFATc1 in the calcification-forming region of early plaque was significantly upregulated, and excite/inhibit CD137-CD137L interaction respectively, the calcium deposition in the carotid artery plaque in the mice was corresponding increased/decreased. In vitro, the expression of NFATc1 in smooth muscle cell-derived osteoblast-like cells was upregulated/downregulated. These findings suggested that CD137-CD137L interaction can regulate plaque calcification initiated by NFATc1.Therefore, this study is to investigate the effects of NFATc1 on plaque calcification formation regulated by CD137-CD137L interaction on the basis of our previous studies. ApoE-/- mice and smooth muscle cells are used as models, over-expression or silencing-expression of NFATc1 respectively to verify that NFATc1 serves as a connecting link between CD137-CD137L interaction and the calcification of atherosclerotic plaque, and investigate its explicit role of the latter. We aim to clarify the mechanism of CD137-CD137L interaction modulate the expression of NFATc1 to control calcification formation of atherosclerotic plaque.

血管钙化特别是位于AS斑块内微钙化灶，极易引起斑块破裂，是造成心肌梗死、血管夹层的重要原因；研究提示：NFATc1发挥调控血管钙化的"分子开关"作用。我们前期发现：ApoE-/-小鼠斑块形成中，NFATc1是受CD137-CD137L轴调控斑块进展的下游分子，在斑块早期钙化形成区，NFATc1表达增强，分别激动/抑制该轴，小鼠颈动脉斑块内钙盐沉积增加/减少，NFATc1在平滑肌细胞源性成骨样细胞表达出现上调和下抑。提示：CD137-CD137L轴通过调控NFATc1 启动血管斑块钙化的形成。本研究拟在前期研究基础上探讨NFATc1在CD137-CD137L轴调控斑块钙化形成中作用。以ApoE-/-小鼠和平滑肌细胞为模型，分别过表达和沉默表达NFATc1，验证NFATc1在该轴中承上启下的作用，明确该轴及NFATc1在AS斑块钙化中的作用。阐明该轴通过NFATc1调控AS斑块钙化形成的机制。

项目在前期基础上，探讨CD137L-CD137信号是否通过NFATc1调控AS斑块钙化形成及机制。.研究发现：在ApoE-/-小鼠及体外培养VSMC中均证实激活CD137-CD137L信号不仅能促进AS钙化形成，而且上调骨形成蛋白BMP2和Runx2表达，促进VSMC成骨分化，诱导VSMC钙化形成。在ApoE-/-体内激活CD137-CD137L能促进斑块新生血管形成，细胞试验证实CD137-CD137L信号通过Smad1/5调控NFATc1影响新生血管形成。并且CD137-CD137L通过NFATc1调控新生内膜形成和VSMC表型转化。CD137-CD137L与NFATc1之间有三条内在信号通路，即CD137-CD137L通过TRAF6/NF-kB、TRAF6/JNK/AP-1及CaM-CaN途径调控NFATc1表达。另外CD137-CD137L还可通过microRNA-124-2及microRNA-145a-5p调控ApoE-/-小鼠斑块及VSMC中NFATc1表达。.研究显示：在体内、外CD137-CD137L信号能够通过调控小鼠VSMC自噬小体出胞及抑制自噬小体与溶酶体融合促进AS钙化形成。CD137-CD137L信号通过CyPA调控ApoE-/-小鼠斑块形成，抑制CyPA能够阻止此过程，并且CyPA通过调节自噬介导OX-LDL导致的巨噬细胞激活和凋亡。CD137-CD137L能够激活胞内PLC信号，包括DAG-PKC和IP3-[Ca2+]i二条信号途径。而细胞膜PKC活性通过PKC-NF-κB/I-κB-ICAM-1影响内皮细胞与单核细胞粘附反应。并且与CD137-CD137L同一家族OX40-OX40L信号具有相似作用，该信号激活能促进斑块中NFATc1/CyPA及ROS表达，并促进斑块形成。.临床发现糖尿病下肢截肢的AS斑块形成中以点灶状钙化为主，其机制是CML/RAGE 信号通过ROS-p38MAPK途径导致钙化形成。ACS患者CD147表达增加；CD147T等位基因是ACS发病的保护因素。采用OCT技术观察了冠脉破裂斑块，并发现CD137水平是冠脉斑块不稳定的标志物。.研究阐明了CD137-CD137L调控NFATc1启动AS斑块钙化形成机制，发表SCI论文14篇，中华16篇。培养研究生12名，获得江苏省医学新技术引进一等奖及科技进步奖3项。