Wang Jian, Sun Yi-Ting, Xu Tian-Hua, Sun Wei, Tian Bin-Yao, Sheng Zi-Tong, Sun Li, Liu Lin-Lin, Ma Jian-Fei, Wang Li-Ning, Yao Li
Department of Nephrology, The First Hospital of China Medical University, Shenyang, China.
Department of Clinical Medicine, China Medical University, Shenyang, China.
Cell Physiol Biochem. 2017;42(2):530-536. doi: 10.1159/000477602. Epub 2017 Jun 5.
BACKGROUND/AIMS: Autophagy is an evolutionarily conserved mechanism that affects the survival and functions of vascular smooth muscle cells (VSMCs). We explored the role of microRNAs (miRNAs) in regulating autophagy in VSMCs exposed to high phosphorus (Pi) levels.
VSMCs were isolated from the thoracic aorta of rats and were cultured primarily. Real-time PCR was used to measure the mRNA expression of indicated genes. Western blotting was performed to detect the protein expression of autophagy-related markers.
We found that treatment with high Pi levels (1 and 3 mM) activated LC3II expression and promoted autophagic flux in VSMCs. Conversely, treatment with an autophagy inhibitor decreased LC3II expression. Pi stimulation dysregulated the expression of several miRNAs such as miR-18a, miR-21, miR-23a, miR-30b, and miR-31a. However, miR-30b overexpression decreased Pi-induced expression of autophagy-related marker genes such as BECN1, ATG5, and LC3b, whereas miR-30b downregulation increased Pi-induced expression of these genes. In addition, we found that miR-30b directly targeted BECN1.
These data suggest that miR-30b plays an important role in the regulation of high Pi level-induced autophagy in VSMCs by targeting BECN1.
背景/目的：自噬是一种进化上保守的机制，影响血管平滑肌细胞（VSMC）的存活和功能。我们探讨了微小RNA（miRNA）在调节高磷（Pi）水平下VSMC自噬中的作用。
从大鼠胸主动脉分离VSMC并进行原代培养。采用实时PCR检测指定基因的mRNA表达。进行蛋白质印迹法检测自噬相关标志物的蛋白质表达。
我们发现高磷水平（1和3 mM）处理可激活VSMC中LC3II的表达并促进自噬流。相反，用自噬抑制剂处理可降低LC3II的表达。Pi刺激使几种miRNA如miR-18a、miR-21、miR-23a、miR-30b和miR-31a的表达失调。然而，miR-30b过表达降低了Pi诱导的自噬相关标志物基因如BECN1、ATG5和LC3b的表达，而miR-30b下调则增加了Pi诱导的这些基因的表达。此外，我们发现miR-30b直接靶向BECN1。
这些数据表明miR-30b通过靶向BECN1在调节高磷水平诱导的VSMC自噬中起重要作用。
