ROCK1 activation-mediated mitochondrial translocation of Drp1 and cofilin are required for arnidiol-induced mitochondrial fission and apoptosis

Abstract

Background: 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. Methods: 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. Results: 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. Conclusions: 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.

Klf5 down-regulation induces vascular senescence through eIF5a depletion and mitochondrial fission

“…Recent studies show that the expressing alteration of Drp1 and/or its mitochondrial translocation regulates mitochondrial fission and apoptosis [54,55], and that VSMC apoptosis could be targetable mechanisms implicated in the pathogenesis of AAA formation [56]. Our results show that loss of Klf5 in VSMCs resulted in Drp1 up-regulation and mitochondrial translocation, which are requisite events in Drp1-dependent mitochondrial fragmentation and cell apoptosis.…”

Cofilin: A Promising Protein Implicated in Cancer Metastasis and Apoptosis

“…Apoptosis is an active, controlled and complicated process, it is the degradation of a highly conserved protein or organelle in eukaryotes (Shi et al, 2020 ). Allyl isothiocyanate (AITC) (Tang et al, 2014 ), urisolic acid (UA) (Li R. et al, 2014 ), etoposide (Chua et al, 2003 ), arnidiol (Hu et al, 2020 ), and 4-methylthiobutyl isothiocyanate (Grzanka et al, 2011 ) can induce apoptosis in several tumor cell lines, such as SH-SY5Y, HL60, COS-7, and HeLa cells (Chua et al, 2003 ), through the cofilin pathway by regulating mitochondrial translocation and fission (Hoffmann et al, 2019 ; Hu et al, 2020 ). The fusion and division of mitochondria are two continuous dynamic antagonistic processes, which maintain the morphology of mitochondria and apoptotic fission plays essential role in cellular physiology (Sheridan and Martin, 2010 ).…”

“…The mitochondrial regulation dominated by cofilin dephosphorylation activation is closely related to Drp1 and PINK1/Park2 pathways (Serasinghe and Chipuk, 2017 ). The direct interaction between cofilin and Drp1 in the outer membrane of mitochondria contributes to mitochondrial division (Estaquier and Arnoult, 2007 ; Hu et al, 2020 ). Knocking down the expression of cofilin or Drp1 will affect their interaction, resulting in the blocking of mitochondria division and the release of cytochrome C and apoptosis (Li et al, 2015 ; Rehklau et al, 2017 ).…”

“…As an important regulator of cancer metastasis, more and more studies explored the potential of cofilin being a therapeutic target in tumors. Activated cofilin translocates to the outer mitochondrial membrane and interacts with dynamin-related protein 1 (Drp1), induces mitochondrial fission and promotes cytochrome C release, finally leading to apoptosis in tumor cells (Hoffmann et al, 2019 ; Hu et al, 2020 ). This review discusses the functional role of cofilin in cancer metastasis and provides evidence for clinical perspective of cofilin in cancer treatment.…”

Recent advances and future directions in anti‐tumor activity of cryptotanshinone: A mechanistic review

“…The newly published articles have examined the role of Drp1 in cancer cells. The interaction between Drp1 and cofilin stimulates apoptosis in cancer cells via mitochondrial fission (Hu et al, 2020). The anti-tumor drugs target Drp1 in cancer therapy.…”