Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China.
Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China; School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, China.
Metabolism. 2021 Jun;119:154768. doi: 10.1016/j.metabol.2021.154768. Epub 2021 Mar 26.
Reducing serum low-density lipoprotein cholesterol (LDL-C) in hyperlipemia is recognized as an effective strategy to minimize the risk of atherosclerotic cardiovascular disease (ASCVD). MiR-337-3p has already been discovered to play regulatory roles in tumor proliferation and metastasis, adipocyte browning and ischemic brain injury, etc. However, the association between miR-337-3p and LDL-C is unknown.
Gene Expression Omnibus (GEO) dataset and two hyperlipidemic murine models were used to analyze the potential relationship between miR-337-3p and LDL-C. AAV-mediated liver-directed miRNA overexpression in high fat diet (HFD)-fed mouse model was used to examine the effect of miR-337-3p on LDL-C and WB/RT-PCR/ELISA/luciferase assays were used to investigate the underlying mechanism.
The expressions of miR-337-3p were obviously lower in multiple hyperlipidemic mouse models and had a negative correlation with serum LDL-C levels. After confirming the effect of miR-337-3p on the improvement of serum LDL-C in vivo, we discovered PCSK9 might be a possible target of miR-337-3p, which was further proved by in vitro experiments. MiR-337-3p could directly interact with both the PCSK9 3'UTR and promoter to inhibit PCSK9 translation and transcription. Furthermore, the result from DiI-LDL uptake assay under the knockdown of PCSK9 demonstrated that miR-337-3p promoting the absorption of LDL-C in HepG2 cells was dependent on PCSK9, and the result from LDLR-/- mouse model indicated that miR-337-3p regulating LDL-C was dependent on PCSK9/LDLR pathway.
We discovered a new function of miR-337-3p in regulating PCSK9 expression and LDL-C absorption, suggesting miR-337-3p might be a new therapeutic target for the development of antihyperlipidemic drug.
降低高脂血症患者的血清低密度脂蛋白胆固醇（LDL-C）被认为是降低动脉粥样硬化性心血管疾病（ASCVD）风险的有效策略。miR-337-3p 已被发现在肿瘤增殖和转移、脂肪细胞棕色化和缺血性脑损伤等方面发挥调节作用。然而，miR-337-3p 与 LDL-C 之间的关系尚不清楚。
使用基因表达综合数据库（GEO）数据集和两种高脂血症小鼠模型来分析 miR-337-3p 与 LDL-C 之间的潜在关系。使用 AAV 介导的肝靶向 miRNA 过表达在高脂肪饮食（HFD）喂养的小鼠模型中，观察 miR-337-3p 对 LDL-C 的影响，并通过 WB/RT-PCR/ELISA/荧光素酶报告基因实验研究其潜在机制。
miR-337-3p 在多种高脂血症小鼠模型中的表达明显降低，与血清 LDL-C 水平呈负相关。在体内证实了 miR-337-3p 对改善血清 LDL-C 的作用后，我们发现 PCSK9 可能是 miR-337-3p 的一个可能靶点，这一结论在体外实验中得到了进一步证实。miR-337-3p 可以直接与 PCSK9 的 3'UTR 和启动子相互作用，抑制 PCSK9 的翻译和转录。此外，在敲低 PCSK9 条件下进行 DiI-LDL 摄取实验的结果表明，miR-337-3p 促进 HepG2 细胞内 LDL-C 的吸收依赖于 PCSK9，而 LDLR-/-小鼠模型的结果表明，miR-337-3p 调节 LDL-C 依赖于 PCSK9/LDLR 途径。
我们发现了 miR-337-3p 在调节 PCSK9 表达和 LDL-C 吸收中的新功能，提示 miR-337-3p 可能成为开发抗高血脂药物的新治疗靶点。
