College of Pharmacy, Army Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, China.
Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China.
J Exp Clin Cancer Res. 2020 Feb 19;39(1):37. doi: 10.1186/s13046-020-01545-7.
Arnidiol is a pentacyclic triterpene diol that has multiple pharmacological activities. However, the apoptotic activities of arnidiol in human cancer cells have not yet been explored, nor has the mechanism by which arnidiol induces apoptosis been examined in depth.
MDA-MB-231 cells and xenografted mice were treated with arnidiol. Mitochondrial fission and apoptosis were determined by immunofluorescence, flow cytometry and related molecular biological techniques. The interaction and colocalization of cofilin and Drp1 was determined by immunoprecipitation and immunofluorescence assays.
Arnidiol induces mitochondrial fission and apoptosis through mitochondrial translocation of Drp1 and cofilin. Importantly, the interaction of Drp1 and cofilin in mitochondria is involved in arnidiol-induced mitochondrial fission and apoptosis. Knockdown of either Drp1 or cofilin abrogated arnidiol-induced mitochondrial translocation, interaction of Drp1 and cofilin, mitochondrial fission and apoptosis. Only dephosphorylated Drp1 (Ser637) and cofilin (Ser3) were translocated to the mitochondria. Mutants of Drp1 S637A and cofilin S3A, which mimic the dephosphorylated forms, enhanced mitochondrial fission and apoptosis induced by arnidiol, whereas mutants of Drp1 S637D and cofilin S3E, which mimic the phosphorylated forms, suppressed mitochondrial fission and apoptosis induced by arnidiol. A mechanistic study revealed that ROCK1 activation plays an important role in the arnidiol-mediated Drp1 and cofilin dephosphorylation and mitochondrial translocation, mitochondrial fission, and apoptosis.
Our data reveal a novel role of both Drp1 and cofilin in the regulation of mitochondrial fission and apoptosis and suggest that arnidiol could be developed as a potential agent for the treatment of human cancer.
Arnidiol 是一种五环三萜二醇，具有多种药理活性。然而，Arnidiol 对人类癌细胞的凋亡活性尚未被探索，也没有深入研究 Arnidiol 诱导细胞凋亡的机制。
用 Arnidiol 处理 MDA-MB-231 细胞和异种移植小鼠。通过免疫荧光、流式细胞术和相关分子生物学技术检测线粒体裂变和细胞凋亡。通过免疫沉淀和免疫荧光实验检测 cofilin 和 Drp1 的相互作用和共定位。
Arnidiol 通过 Drp1 和 cofilin 的线粒体易位诱导线粒体裂变和细胞凋亡。重要的是，线粒体中 Drp1 和 cofilin 的相互作用参与了 Arnidiol 诱导的线粒体裂变和细胞凋亡。敲低 Drp1 或 cofilin 均可阻断 Arnidiol 诱导的线粒体易位、Drp1 和 cofilin 的相互作用、线粒体裂变和细胞凋亡。只有去磷酸化的 Drp1（Ser637）和 cofilin（Ser3）易位到线粒体。模拟去磷酸化形式的 Drp1 S637A 和 cofilin S3A 突变体增强了 Arnidiol 诱导的线粒体裂变和细胞凋亡，而模拟磷酸化形式的 Drp1 S637D 和 cofilin S3E 突变体则抑制了 Arnidiol 诱导的线粒体裂变和细胞凋亡。机制研究表明，ROCK1 激活在 Arnidiol 介导的 Drp1 和 cofilin 去磷酸化及线粒体易位、线粒体裂变和细胞凋亡中起重要作用。
本研究揭示了 Drp1 和 cofilin 在调控线粒体裂变和凋亡中的新作用，并提示 Arnidiol 可被开发为治疗人类癌症的潜在药物。
