lincRNA-FA2H-2-MLKL途径介导OX-LDL对细胞焦亡和AS的影响及机制研究

Pyroptosis is a newly found form of programmed cell death, which is dependent on caspase-1 activation and leads to the release of pro-inflammatory cytokines. It is well established oxidized low-density lipoprotein (OX-LDL) promotes caspase-1 mediated pyroptotic cell death and plays a crucial role in the initiation and progression of atherosclerosis, and long non-coding RNA (lncRNA) might involve in OX-LDL-induced atherosclerosis development. In addition, atherosclerosis development can be affected by the mixed lineage kinase domain-like protein (MLKL) through regulating pyroptosis. Our preliminary data showed that expression levels of lincRNA-FA2H-2 and MLKL were significantly up-regulated and pyroptosis was increased in OX-LDL-induced THP-1 macrophages. Moreover, we demonstrated that MLKL expression levels and pyroptosis were markedly up-regulated by overexpression of lincRNA-FA2H-2 in THP-1 macrophages. Thus, we hypothesize that pyroptosis and atherosclerosis development can be affected by OX-LDL through inducing lincRNA-FA2H-2 and MLKL expression. In this study, we aim to explore the effect and mechanism of OX-LDL-lincRNA-FA2H-2-MLKL pathway on pyroptosis and atherosclerosis development by enhancing or inhibiting expression of lincRNA-FA2H-2 and/or MLKL. Therefore, our study may provide a new scientific evidence to establish OX-LDL-lincRNA-FA2H-2-MLKL pathway as a new target for regulation of pyroptosis and prevention of atherosclerosis.

细胞焦亡是近年来被发现的一种新型程序性细胞死亡方式，其特征为依赖半胱天冬酶-1(caspase-1)并伴有大量促炎症因子释放。研究表明OX-LDL可通过调节细胞焦亡进而影响AS发生发展，lncRNA可能介导OX-LDL调节AS的发生发展，MLKL可通过调节细胞焦亡过程影响AS的进展。我们的前期预实验结果证明OX-LDL可上调lincRNA-FA2H-2和MLKL表达并促进细胞焦亡，过表达lincRNA-FA2H-2能明显促进MLKL表达和巨噬细胞焦亡。因此我们提出lincRNA-FA2H-2-MLKL途径可能介导OX-LDL调控细胞焦亡从而影响AS发生发展。本项目拟通过增强/抑制lincRNA-FA2H-2和/或MLKL表达，观察OX-LDL-lincRNA-FA2H-2-MLKL途径对细胞焦亡和AS的影响并探讨相关机制，为确定该途径可作为调控细胞焦亡和防治AS的新靶点提供科学依据。

动脉粥样硬化（AS）是一种慢性、炎症性相关疾病，最新研究发现 lncRNAs 在心血管疾病中发挥重要的作用，但是关于 lncRNAs 在 As 中的具体机制尚不清楚，本研究主要发现如下：.1. OX-LDL 所诱导的炎症反应可能是由于自噬流受损所致， 而自噬流受损的原因可能是由于溶酶体功能受损所致。.2.OX-LDL 可浓度依赖性的降低 LncRNA-FA2H-2 的表达和升高 MLKL 的表达，在动脉粥样硬化斑块组织中 lncRNA-FA2H-2 的表达降低，而 MLKL 的表达升高。此外我们还发现 lncRNA-FA2H-2 可在 DNA 转录水平参与调控MLKL。.3.在体外 RNA-FA2H-2 可逆转 OX-LDL 所致的自噬流的损伤而激活自噬流，而 lncRNA-FA2H-2 导致的自噬流的活化可减轻 OX-LDL 所诱导的炎症反应。在体内我们发现 lncRNA-FA2H-2 可减轻动脉粥样硬化斑块的炎症反应，其可能的机制是由于自噬活化所致。.4. MLKL 可加重 OX-LDL 所诱导的炎症反应，其可能的机制是由于自噬流受抑制所致，此外 MLKL 可能是以一种 mTOR 依赖性的方式调节自噬。.综上所述，我们的研究进一步揭示了 lncRNA-FA2H-2 在动脉粥样硬化过程中的作用， 为 lncRNAs 作为潜在的治疗靶点提供实验依据，并且为动脉粥样硬化的预防以及临床治疗提供新的指导方向。