长链非编码RNATUG1调控miR-137参与局灶性脑缺血大鼠神经损伤的作用机制

目的 探讨长链非编码RNA牛磺酸上调基因1(Long non-coding RNA taurine upregulation gene 1,LncRNA TUG1)调控微小RNA(MicroRNA,miR)-137参与局灶性脑缺血大鼠神经损伤的作用机制。方法 将大鼠分为假手术组、模型组、过表达LncRNA TUG1组、敲低LncRNA TUG1组、空质粒(NC)组; Longa法评估大鼠神经功能; 大鼠脑组织称重,计算脑组织含水量; 脑组织2,3,5-三苯基氯化四氮唑(2,3,5-Triphenyltetrazolium chloride,TTC)染色观察脑梗死情况; 脑组织尼氏染色观察海马CA1区神经细胞受损情况; 比色法检测脑组织中半胱氨酰天冬氨酸特异性蛋白酶(Cysteing aspartate-spe-cific protease,Caspase)-3和Caspase-9活性; 实时定量聚合酶链反应(Real-time quantitative polymerase chain reaction,RT-qPCR)检测脑组织中LncRNA TUG1和miR-137的表达水平; 双荧光素酶法检测TUG1和miR-137靶向关系; 蛋白质免疫印迹(Western blot,WB)检测脑组织中丝裂原活化蛋白激酶激活蛋白激酶2(Mitogen-activated protein kinase activated protein kinase 2,MK2)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白细胞介素-6(Interleukin-6,IL-6)的表达水平。结果 与假手术组比较,模型组、NC组神经功能损伤评分、脑梗死占比、Caspase-3和Caspase-9活性、LncRNA TUG1以及MK2,TNF-α,IL-6表达水平均显著升高,miR-137表达水平显著降低(P<0.05); 与模型组比较,过表达LncRNA TUG1组神经功能损伤评分、脑梗死占比、Caspase-3和Caspase-9活性、LncRNA TUG1以及MK2,TNF-α,IL-6表达水平均显著升高,miR-137表达水平显著降低(P<0.05),敲低LncRNA TUG1组神经功能损伤评分、脑梗死占比、Caspase-3和Caspase-9活性、LncRNA TUG1以及MK2,TNF-α,IL-6表达水平均显著降低,miR-137表达水平显著升高(P<0.05)。结论 LncRNA TUG1通过抑制miR-137表达来调控MK2介导的炎症反应,从而促进局灶性脑缺血大鼠神经损伤。

Regulatory mechanism of long non-coding RNA TUG1 on nerve injury in rats with by regulating miR-137

ObjectiveTo explore the mechanism of long non-coding RNA TUG1(LncRNA TUG1)in nerve injury of rats with focal cerebral ischemia by regulating miR-137.Methods Rats were divided into sham operation group, model group, LncRNA TUG1 over expression group, LncRNA TUG1 knockdown group and NC(empty plasmid)group. Nerve function was evaluated by Longa method; the brain tissue was weighed and the brain water content was calculated; the infarction and the neurons in hippocampal CA1 area were observed by TTC staining and Nissl staining respectively; the activities of Caspase-3 and Caspase-9 in brain tissue were detected by colorimetry; the expression of LncRNA TUG1 and miR-137 in brain tissue were detected by real-time quantitative polymerase chain reaction(RT-qPCR); the targeting relationship between TUG1 and miR-137 was detected by dual luciferase assay; the expression of mitogen-activated protein kinase activated protein kinase 2(MK2), tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in brain tissue were detected by Western blot.Results Compared with those in the sham operation group, the neurological impairment score, cerebral infarction rate, activities of Caspase-3 and Caspase-9, expression of LncRNA TUG1, MK2, TNF-α and IL-6 in the model group and NC group were significantly higher, the expression of miR-137 was significantly lower(P<0.05).Compared with those in the model group, the neurological impairment score, cerebral infarction rate, activities of Caspase-3 and Caspase-9, expression of LncRNA TUG1, MK2, TNF-α and IL-6 in the LncRNA TUG1 overexpression group were significantly higher, the expression of miR-137 was significantly lower(P<0.05), the neurological impairment score, cerebral infarction rate, activities of Caspase-3 and Caspase-9, expression of LncRNA TUG1, MK2, TNF-α and IL-6 in the LncRNA TUG1 knockdown group were significantly lower, the expression of miR-137 was significantly higher(P<0.05).Conclusion LncRNA TUG1 can regulate MK2-mediated inflammatory response by inhibiting the expression of miR-137, thus promoting nerve injury in rats with focal cerebral ischemia.