Inhibition of DRP1 Impedes Zygotic Genome Activation and Preimplantation Development in Mice

Abstract

Mitochondrion plays an indispensable role during preimplantation embryo development. Dynamic-related protein 1 (DRP1) is critical for mitochondrial fission and controls oocyte maturation. However, its role in preimplantation embryo development is still lacking. In this study, we demonstrate that inhibition of DRP1 activity by mitochondrial division inhibitor-1, a small molecule reported to specifically inhibit DRP1 activity, can cause severe developmental arrest of preimplantation embryos in a dose-dependent manner in mice. Meanwhile, DRP1 inhibition resulted in mitochondrial dysfunction including decreased mitochondrial activity, loss of mitochondrial membrane potential, reduced mitochondrial copy number and inadequate ATP by disrupting both expression and activity of DRP1 and mitochondrial complex assembly, leading to excessive ROS production, severe DNA damage and cell cycle arrest at 2-cell embryo stage. Furthermore, reduced transcriptional and translational activity and altered histone modifications in DRP1-inhibited embryos contributed to impeded zygotic genome activation, which prevented early embryos from efficient development beyond 2-cell embryo stage. These results show that DRP1 inhibition has potential cytotoxic effects on mammalian reproduction, and DRP1 inhibitor should be used with caution when it is applied to treat diseases. Additionally, this study improves our understanding of the crosstalk between mitochondrial metabolism and zygotic genome activation.

Regulation of cleavage embryo genes upon DRP1 inhibition in mouse embryonic stem cells

“…Mitochondria are important and dynamic double membrane-bound organelles, and the balance of fission and fusion maintains their physiological functions ( Youle and van der Bliek, 2012 ; Wai and Langer, 2016 ; Giacomello et al, 2020 ; Li et al, 2021 ). The guanosine triphosphatases (GTPases), which are well conserved in mammals, are responsible for this dynamic process ( Youle and van der Bliek, 2012 ; Wai and Langer, 2016 ).…”

“…The guanosine triphosphatases (GTPases), which are well conserved in mammals, are responsible for this dynamic process ( Youle and van der Bliek, 2012 ; Wai and Langer, 2016 ). As for the fission process, the dynamic-related protein 1 (DRP1), a member of the cytosolic dynamin family, is recruited by Mid49 , Mid51 , and Mff to function in mammalian mitochondria ( Schmitt et al, 2018 ; Kleele et al, 2021 ; Li et al, 2021 ). Mitochondrial fission is essential for development, and it is demonstrated that the knockout of Drp 1 in mice caused death of early embryos.…”

“…Mitochondrial fission is essential for development, and it is demonstrated that the knockout of Drp 1 in mice caused death of early embryos. In addition, the loss of Drp1 seriously affects the maturation of oocytes and the establishment of maternal epigenome in preimplantation embryos ( Udagawa et al, 2014 ; Li et al, 2021 ; Adhikari et al, 2022 ). Interestingly, the CRISPR-Cas9 system has been used to generate DRP1-knockout embryonic stem cells (ESCs), which showed significantly impacted mitochondrial metabolism and global gene expression profiles ( Seo et al, 2020 ).…”

“…The intermediates in the mitochondrial metabolic pathway are closely related to key enzymes, which regulate chromatin and protein modification such as histones, methylation, and acetylation ( Gafni et al, 2013 ; Carbognin et al, 2016 ; Matilainen et al, 2017 ; Zhang et al, 2018 ). Upregulation of mitochondrial transcripts and metabolism with activated STAT3 promotes the proliferation of mouse ESCs and the reprogramming of EpiSCs ( Li et al, 2021 ). The inhibition of histone deacetylase (HDAC), which is dependent on NAD + , drove ESCs to a more naive state in vitro ( Giacomello et al, 2020 ).…”

“…Our previous studies have shown that DRP1 deactivation led to mitochondrial abnormalities and thus affected the normal development of embryos ( Li et al, 2021 ), but its effect on cell fate control remains unclear. In particular, mitochondrial division inhibitor-1 (Mdivi-1), which can inhibit the activity of DRP1, has been proposed to selectively inhibit mitochondrial division in mammals ( Cassidy-Stone et al, 2008 ; Bordt et al, 2017 ).…”