Intensive Care Unit, The Second People's Hospital of Heifei, Hefei, China.
Intensive Care Unit, Anhui Provincial Hospital, the First Affiliated Hospital of University of Science and Technology of China, Heifei, China.
Cell Biochem Funct. 2020 Oct;38(7):976-985. doi: 10.1002/cbf.3524. Epub 2020 Mar 17.
This work aims to investigate the function and mechanism of long non-coding RNA (lncRNA) cytoskeleton regulator RNA (CYTOR) in myocardial injury induced by sepsis. The sepsis-induced myocardial injury model in mice was established by intraperitoneal injection of LPS (10 mg/kg) in vivo, and cardiomyocyte H9c2 was treated with LPS to mimic sepsis in vitro. CYTOR expression and miR-24 expression were detected by qRT-PCR. After up-regulation or down-regulation of CYTOR and miR-24 expression in the H9c2 cells, and the viability of the cells was detected via MTT assay, and cell apoptosis was detected by TUNEL assay. Western blot was applied to determine the expression level of caspase 3, Bax and X-chromosome-linked inhibitor of apoptosis (XIAP). Interaction between CYTOR and miR-24 was determined by bioinformatics analysis, RT-PCR and dual luciferase reporter assay. Interaction between miR-24 and XIAP was determined through bioinformatics analysis, RT-PCR, western blot and dual luciferase reporter assay. CYTOR was markedly down-regulated. CYTOR interacted with miR-24, and negatively regulated its expression level. Over-expression of CYTOR or transfection of miR-24 inhibitors significantly promoted viability and inhibited apoptosis of H9c2 cells, while the knockdown of CYTOR and transfection of miR-24 mimics had opposite effects. CYTOR suppressed the expression level of apoptosis-related proteins, but miR-24 increased them. miR-24 directly targeted the 3'UTR of XIAP, and suppressed it, and XIAP was modulated indirectly by CYTOR. Down-regulation of CYTOR aggravates sepsis-induced cardiac injury via regulating miR-24 and XIAP.
本研究旨在探讨长链非编码 RNA（lncRNA）细胞骨架调节 RNA（CYTOR）在脓毒症诱导心肌损伤中的作用及机制。通过体内腹腔注射 LPS（10mg/kg）建立脓毒症诱导的小鼠心肌损伤模型，体外采用 LPS 处理心肌细胞 H9c2 模拟脓毒症。采用 qRT-PCR 检测 CYTOR 表达和 miR-24 表达。上调或下调 H9c2 细胞中 CYTOR 和 miR-24 的表达后，通过 MTT 检测细胞活力，通过 TUNEL 检测细胞凋亡。Western blot 检测 caspase 3、Bax 和 X 染色体连锁凋亡抑制蛋白（XIAP）的表达水平。通过生物信息学分析、RT-PCR 和双荧光素酶报告基因检测确定 CYTOR 与 miR-24 之间的相互作用。通过生物信息学分析、RT-PCR、western blot 和双荧光素酶报告基因检测确定 miR-24 与 XIAP 之间的相互作用。结果显示，脓毒症时 CYTOR 表达明显下调。CYTOR 与 miR-24 相互作用，负调控其表达水平。过表达 CYTOR 或转染 miR-24 抑制剂显著促进 H9c2 细胞活力并抑制细胞凋亡，而敲低 CYTOR 或转染 miR-24 模拟物则产生相反的效果。CYTOR 抑制凋亡相关蛋白的表达水平，而 miR-24 则增加它们的表达。miR-24 直接靶向 XIAP 的 3'UTR，抑制其表达，而 XIAP 则通过 CYTOR 间接调节。下调 CYTOR 通过调节 miR-24 和 XIAP 加重脓毒症诱导的心脏损伤。
