Zhang Wenting, Meng Aiguo
Department of Laboratory Medicine, Affiliated Hospital and School of Clinical Medicine, North China University of Science and Technology, Tangshan, Hebei 06300, P.R. China.
Exp Ther Med. 2019 Apr;17(4):2870-2876. doi: 10.3892/etm.2019.7220. Epub 2019 Jan 30.
Cerebral ischemia and reperfusion injury is a cause of death and disability in adults. MicroRNA-124 possesses protective effects against apoptosis in cerebral ischemia and reperfusion. To provide insights into the diagnosis and treatment of cerebral ischemia and reperfusion injury, the dynamic changes of microRNA-124 expression during the early stage of cerebral ischemia and reperfusion injury in rats was investigated by quantitative polymerase chain reaction. To elucidate the association between the dynamic expression of microRNA-124 and apoptosis, the expression of proteins associated with apoptosis, including caspase-3, apoptosis regulator Bcl-2 (Bcl-2) and apoptosis regulator Bax (Bax) was analyzed by immunohistochemistry and western blot analyses. As signal transducer and activator of transcription 3 (STAT3) is involved in cell apoptosis and associated with Bcl-2, the protein expression of STAT3 and its active form, phosphorylated (p-)STAT3, were analyzed by western blot analysis. The expression of microRNA-124 increased and the maximum value appeared 12 h after reperfusion. Similarly, the expression of Bcl-2 also peaked 12 h after reperfusion, however the expression of caspase-3 and Bax continued to increase after the 12 h time point. These results indicate that the expression of microRNA-124 is closely associated with Bcl-2 and serves a protective role, inhibiting apoptosis. As the upstream regulator of Bcl-2, the expression of p-STAT3 was in accordance with Bcl-2 expression and peaked 12 h after reperfusion. By contrast, STAT3 was downregulated and the minimum level of STAT3 protein was reached 12 h after reperfusion. In summary, during the early stage of cerebral ischemia and reperfusion, the dynamic expression of microRNA-124 exhibited protective effects through the inhibition of apoptosis via anti-apoptotic proteins Bcl-2 and STAT3. Conversely, caspase-3 and Bax maintain apoptosis. The present study provides evidence to aid in the understanding of cerebral ischemia and reperfusion injury and develops methods of diagnosis and therapy of this condition.
脑缺血再灌注损伤是成年人死亡和致残的一个原因。微小RNA-124对脑缺血再灌注中的细胞凋亡具有保护作用。为了深入了解脑缺血再灌注损伤的诊断和治疗，通过定量聚合酶链反应研究了大鼠脑缺血再灌注损伤早期微小RNA-124表达的动态变化。为了阐明微小RNA-124的动态表达与细胞凋亡之间的关联，通过免疫组织化学和蛋白质印迹分析对与细胞凋亡相关的蛋白质表达进行了分析，这些蛋白质包括半胱天冬酶-3、凋亡调节蛋白Bcl-2（Bcl-2）和凋亡调节蛋白Bax（Bax）。由于信号转导子和转录激活子3（STAT3）参与细胞凋亡并与Bcl-2相关，通过蛋白质印迹分析对STAT3及其活性形式磷酸化（p-）STAT3的蛋白质表达进行了分析。微小RNA-124的表达增加，在再灌注后12小时出现最大值。同样，Bcl-2的表达也在再灌注后12小时达到峰值，然而，半胱天冬酶-3和Bax的表达在12小时时间点后继续增加。这些结果表明，微小RNA-124的表达与Bcl-2密切相关，并发挥保护作用，抑制细胞凋亡。作为Bcl-2的上游调节因子，p-STAT3的表达与Bcl-2表达一致，在再灌注后12小时达到峰值。相比之下，STAT3被下调，在再灌注后12小时达到STAT3蛋白的最低水平。总之，在脑缺血再灌注早期，微小RNA-124的动态表达通过抗凋亡蛋白Bcl-2和STAT3抑制细胞凋亡而发挥保护作用。相反，半胱天冬酶-3和Bax维持细胞凋亡。本研究为帮助理解脑缺血再灌注损伤以及开发这种病症的诊断和治疗方法提供了证据。
