Description
Mdivi 1 is a mitochondrial division inhibitor. It inhibits the GTPase activity of yeast, but not human, dynamin-1 (Dnm1; IC50 = ~1-10 μM for the recombinant yeast enzyme) and human dynamin-related protein 1 (DRP1) in A549 lung cancer cells when used at a concentration of 50 μM. Mdivi 1 (50 μM) inhibits mitochondrial fragmentation and DRP1 self-assembly induced by staurosporine in COS cells overexpressing DRP1. It induces apoptosis in, and inhibits colony formation of, A549 cells when used at concentrations of 25 and 50 μM, respectively. Mdivi 1 (1 μM) decreases doxorubicin-induced increases in infarct-to-risk ratios in a Langendorff isolated perfused rat heart model of ischemia-reperfusion injury. It reduces the severity of lung injury in a mouse model of LPS-induced acute lung injury when administered at a dose of 20 mg/kg.
Uses
Mdivi-1 is a selective inhibitor of mitochondrial division in yeast and mammalian cells which acts via inhibiting the mitochondrial division dynamin. In cells, Mdivi-1 inhibits apoptosis by inhibiting mitochondrial outer membrane permeabilization. Mdivi-1 causes the rapid (<5 min) reversible and dose-dependent formation of net-like mitochondria in wild-type cells with an IC50= ~10μM. In yeast, time-lapse fluorescence microscopy revealed no detectable mitochondrial division after treatment with Mdivi-1. It inhibits Dnm1 GTPase activity in a dose dependent manner with an estimated IC50 of 1-10μM but is not a general inhibitor of GTPases.
General Description
Mitochondrial Division Inhibitor 1 (Mdivi-1) is a quinazolinone derivative and is cell permeable. It traverses blood-brain barrier and elicits protective functionality in heart and brain ischemia-reperfusion injury.
Biological Activity
Mdivi-1 (Mitochondrial division inhibitor 1) is a selective and cell-penetrating inhibitor of mitochondrial division, inhibits DRP1 (dynamin-related GTPase) and Dynamin I (Dnm1) with IC50 of 1-10 μM. Mdivi-1 reduces mitophagy and increases apoptosis.
Biochem/physiol Actions
Mdivi-1 is a cell-permeable selective inhibitor of mitochondrial division DRP (dynamin-related GTPase) and inhibitor of the mitochondrial division dynamin (Dnm1). Mitochondrial fusion and division play important roles in the regulation of apoptosis. Mdivi-1 is the first selective inhibitor of mitochondrial division dynamins. In principle, Mdivi-1 represents a class of therapeutics for stroke, myocardial infarction, and neurodegenerative diseases.
in vitro
Mdivi-1 is a membrane-crossing quinazolone that inhibits the cleavage of DRPs (dynamin-associated GTPases) by yeast Dnm1 and human Drp1, and induces mitochondrial fusion into a nest-like structure efficiently and reversibly. Extracellular studies suggest that mdivi-1 blocks the ATPase activity (IC50<10 μM) and self-assembly of Dnm1 through allosteric regulation. Mdivi-1 potently inhibited STS and C8-Bid-induced MOMP (increased mitochondrial outer membrane permeability) in HeLa cells and extracellular murine hepatocyte mitochondrial preparations, respectively. In cells, mdivi-1 further inhibited apoptosis by inhibiting mitochondrial outer membrane permeability. In general, mivi-1 represents a class of therapies for the treatment of stroke, myocardial infarction and neurodegenerative diseases.
in vivo
The protein expression of Drp1 and GFAP is significantly increased during early neural development in the retina of ischemic mice. The use of Mdivi-1 blocked apoptosis in the ischemic retina and significantly increased RGC survival after two weeks of ischemia. In normal mouse retina, the expression of Drp1 is mainly distributed in the ganglion cell layer (GCL), the inner plexiform layer, the inner nuclear layer (INL) and the outer plexiform layer. In the ganglion cell layer, Drp1 is strongly immunoreactive. Drp1 protein expression was increased in GCLs 12 h after ischemia induction. Mdivi-1 did not alter the increase in Drp1 protein expression but significantly decreased GFAP protein expression.
References
1) Cassidy-Stone et al. (2008), Chemical inhibition of the mitochondrial division dynamin reveals its role in Bax/Bak-dependent mitochondrial outer membrane permeabilization; Dev. Cell, 14 193
2) Lackner et al. (2010), Small molecule inhibitors of mitochondrial division: tools that translate basic biological research into medicine; Chem. Biol., 17 578
