LncRNA J13Rik调控TXNIP/NLRP3信号通路介导肠缺血再灌注脑损伤后 小胶质细胞极化的机制研究

We have found that microglia (MG)- mediated inflammation is involved in the intestinal ischemia-reperfusion (I/R) induced-brain damage, but the exact molecular mechanism is not clear. Recent studies have found that long non-coding RNA plays an important role in regulating inflammatory response. Microglia can be polarized into pro-inflammatory M1 and anti-inflammatory M2 cells, but the exact mechanism of polarization needs to be clarified.Our preliminary experiments have shown that intestinal I/R could lead to the overexpression of lncRNA J13Rik in mouse’s hippocampal tissue and microglia, and down-regulation of lncRNA J13Rik expression can convert microglia from M1 to M2.Bioinformatics analysis indicated that lncRNA J13Rik could specifically bind TXNIP, which was significantly correlated with TXNIP/NLRP3 signaling pathway.Accordingly, we hypothesized that lncRNA J13Rik could influence brain injury by regulating the TXNIP/NLRP3 signaling pathway to mediate the polarization of microglia after intestinal I/R.This study will further explore the role of lncRNA in the occurrence of intestinal I/R induced-brain injury and verify the hypothesis in vitro and in vivo based on the use of ChIP and RNAi methods, combined with the intervention of expression.This project is expected to reveal the new mechanism of intestinal I/R induced-brain injury and provide new targets and scientific basis for its prevention and treatment.

我们已证实小胶质细胞（MG）介导的炎症反应参与肠缺血再灌注（I/R）所致脑损伤，但机制尚不清楚。近年研究发现长链非编码RNA在调节炎症反应中起重要作用。MG可极化为促炎性M1和抗炎性M2型细胞，但极化的确切机制也需澄清。我们预实验发现肠I/R可致小鼠海马及MG中lncRNA J13Rik高表达，下调该lncRNA表达能使MG由M1转化为M2型。生物信息学分析提示lncRNA J13Rik能特异性结合TXNIP，与TXNIP/NLRP3信号通路显著相关。据此，我们提出假说：lncRNA J13Rik可通过调控TXNIP/NLRP3信号通路，介导肠I/R后MG极化，从而影响脑损伤。本课题拟进一步采用ChIP及RNAi等方法，通过干预表达，在体内外实验水平验证该假说，以深入探讨lncRNA在肠I/R脑损伤发生过程中的作用。本项目有望揭示肠I/R诱发脑损伤的新机制，为其防治提供新靶点及科学依据。

肠缺血再灌注(I/R)损伤是临床上复杂、多因素的病理生理过程，常见于急性肠梗阻、肠扭转、休克、严重烧伤、重度感染及腹主动脉瘤手术等临床现象中。其可以导致肠道自身损伤及远隔多器官损伤，具有发病率及致死率高等特点。肠I/R后肠损伤及远隔多器官损伤的发生机制，目前尚不明确。我们前期已经证实肠I/R可以诱发脑损伤，及小胶质细胞介导的炎症反应参与了肠I/R所致脑损伤，但具体机制也尚不清楚。新近研究发现长链非编码RNA在调节炎症反应中起重要作用。本项目完成了对肠I/R后小鼠海马组织lncRNAs芯片筛查及应用形态学、分子生物学等技术，检测了肠I/R后肠组织及脑组织的组织形态学及相关分子通路TXNIP/NLRP3蛋白表达的变化，着重评估海马组织损伤情况。同时检测了炎性因子及凋亡相关情况，及观察小鼠认知功能变化。研究结果发现肠I/R可致小鼠海马及小胶质细胞中lncRNA J13Rik高表达，下调该lncRNA表达能增加神经细胞的生存活力，抑制神经细胞凋亡，改善脑损伤及认知功能损害，调节小胶质细胞表型极化，促使小胶质细胞由M1转化为M2型，并且能够抑制TXNIP/NLRP3信号通路激活。同时研究中发现肠I/R后海马中Irisin表达增加。研究表明Irisin具有抗炎特性，但是否具有抗肠I/R后肠损伤及远隔多器官损伤的作用，目前尚不清楚。本研究采用小鼠肠I/R在体模型及LPS处理BV2细胞的离体模型，发现Irisin通过抑制TXNIP/NLRP3信号通路激活，减少炎症反应及氧化损伤，抑制神经细胞凋亡，减轻脑损伤，提高肠I/R小鼠的生存率，提示Irisin是潜在的治疗肠I/R后脑损伤的靶点。上述研究结果不仅系统性揭示了肠I/R所致脑损伤的可能相关机制，且提出了可能的干预措施。