Jiao Genlong, Pan Bin, Zhou Zhigang, Zhou Lin, Li Zhizhong, Zhang Ziyong
Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510632, P.R. China.
Department of Surgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510632, P.R. China.
Mol Med Rep. 2015 Nov;12(5):7011-6. doi: 10.3892/mmr.2015.4265. Epub 2015 Aug 28.
Oxidative stress can alter the expression level of microRNAs (miRNAs) and has a role in oxidative damage generated by reactive oxygen species (ROS). While previous studies have demonstrated that miR‑146a, miR‑21 and miR‑150 are essential for ROS production in heart disease, the role of these miRNAs in spinal cord injuries has not yet been examined. The present study focused on examining the role of miR‑146a, miR‑21 and miR‑150 during H2O2 stimulation in rat neuronal spinal cord (RN‑sc) cells. RN‑sc cells were treated with H2O2, and cells were harvested for reverse transcription quantitative polymerase chain reaction (RT‑qPCR) to detect the expression levels of miR‑146a, miR‑21 and miR‑150. The results demonstrated that miR‑146a, miR‑21 and miR‑150 expression was upregulated during H2O2 treatment. T-cell death and apoptosis were investigated using an MTT assay and flow cytometric analysis, respectively. Following miR‑21 silencing, H2O2‑induced cell death and apoptosis were reduced in RN‑sc cells, while miR‑150 silencing had no effect. Furthermore, Smad7 was identified as a direct target of miR‑21 using a Luciferase reporter assay, RT-qPCR and western blot analysis. In addition, while H2O2 downregulated Smad7 protein expression, this was reversed by inhibiting miR‑21 expression. Based on previous studies, it was predicted that miR‑21 has a role in ROS production through regulating Smad7 in rat spinal cord neurons.
氧化应激可改变微小RNA（miRNA）的表达水平，并在活性氧（ROS）产生的氧化损伤中发挥作用。虽然先前的研究表明，miR-146a、miR-21和miR-150在心脏病中ROS产生过程中至关重要，但这些miRNA在脊髓损伤中的作用尚未得到研究。本研究着重探讨miR-146a、miR-21和miR-150在过氧化氢刺激大鼠神经元脊髓（RN-sc）细胞过程中的作用。用过氧化氢处理RN-sc细胞，然后收获细胞用于逆转录定量聚合酶链反应（RT-qPCR），以检测miR-146a、miR-21和miR-150的表达水平。结果表明，在过氧化氢处理期间，miR-146a、miR-21和miR-150的表达上调。分别使用MTT法和流式细胞术分析研究T细胞死亡和凋亡情况。miR-21沉默后，过氧化氢诱导的RN-sc细胞死亡和凋亡减少，而miR-150沉默则无作用。此外，使用荧光素酶报告基因检测、RT-qPCR和蛋白质印迹分析确定Smad7是miR-21的直接靶点。另外，虽然过氧化氢下调了Smad7蛋白表达，但通过抑制miR-21表达可使其逆转。基于先前的研究，预测miR-21通过调节大鼠脊髓神经元中的Smad7在ROS产生中发挥作用。
