Mdivi-1, mitochondrial fission inhibitor, impairs developmental competence and mitochondrial function of embryos and cells in pigs

Abstract

Mitochondria are highly dynamic organelles that undergo constant fusion/fission as well as activities orchestrated by large dynamin-related GTPases. These dynamic mitochondrial processes influence mitochondrial morphology, size and function. Therefore, this study was conducted to evaluate the effects of mitochondrial fission inhibitor, mdivi-1, on developmental competence and mitochondrial function of porcine embryos and primary cells. Presumptive porcine embryos were cultured in PZM-3 medium supplemented with mdivi-1 (0, 10 and 50 μM) for 6 days. Porcine fibroblast cells were cultured in growth medium with mdivi-1 (0 and 50 μM) for 2 days. Our results showed that the rate of blastocyst production and cell growth in the mdivi-1 (50 μM) treated group was lower than that of the control group (P < 0.05). Moreover, loss of mitochondrial membrane potential in the mdivi-1 (50 μM) treated group was increased relative to the control group (P < 0.05). Subsequent evaluation revealed that the intracellular levels of reactive oxygen species (ROS) and the apoptotic index were increased by mdivi-1 (50 μM) treatment (P < 0.05). Finally, the expression of mitochondrial fission-related protein (Drp 1) was lower in the embryos and cells in the mdivi-1-treated group than the control group. Taken together, these results indicate that mdivi-1 treatment may inhibit developmental competence and mitochondrial function in porcine embryos and primary cells.

Mitochondrial Reactive Oxygen Species at the Heart of the Matter

“…Recent work on mdivi-1 in porcine embryos and primary cells showed that mdivi-1 reduces cell growth, blastocyst production, and mitochondrial membrane potential while increasing ROS production. 48 Whereas mdivi-1 inhibits excessive fission under stress conditions as with the IR model, mdivi-1 may also inhibit other functions of Drp1, including healthy physiological fission (Figure 2A). This is consistent with the observation that a Drp1 knockout interferes with mitochondrial clearance and is lethal.…”

The Emerging Role of Mitochondrial Targeting in Kidney Disease

“…Unlike dynasore, mitochondrial division inhibitor (Mdivi)-1 selectively inhibits DRP-1 activity by blocking its assembly, acting through the GTPase domain (Cassidy-Stone et al 2008). Although treatment of porcine preimplantation embryos and fibroblast cells with mdivi-1 reduces mitochondrial membrane potential and blastocyst cell number, increasing ROS and apoptosis (Yeon et al 2015), its delivery in vivo inhibits mPTP opening and protects cardiomyocytes exposed to renal (Sumida et al 2015) and cardiac (Ong et al 2010) IRI. Furthermore, intraperitoneal injections of mdiv-1 prevent mitochondrial fragmentation and tubular cell apoptosis in murine AKI (Tang et al 2013).…”

The Role of Mitochondria in Oocyte and Early Embryo Health

“…Thus, it is not surprising that mitochondrial fission is also essential for proper embryonic development. Mdivi-1, an inhibitor of Drp1, a GTPase involved in mitochondrial fission, was shown to decrease the rate of blastocyst formation of porcine embryos when added to a culture medium [65]. Whole animal knockout of the Drp1 gene resulted in embryo demise at ~E12 [66,67], similar to a phenotype caused by Mfn2-deficiency as these embryos also lacked a proper trophoblast giant cell layer [67].…”