Mdivi-1 (Mitochondrial division inhibitor 1) is a mitochondrial division inhibitor that inhibits DRP1 and Dynamin I (IC50=1-10 μM). Mdivi-1 inhibits mitochondrial autophagy.

Dnm1 GTPase:1 μM-10 μM

In the ganglion cell layer (GCL), Mdivi-1 exhibits strong immunoreactivity. Twelve hours following ischemic induction, Mdivi-1 significantly increases protein expression within the GCL. It notably reduces the expression of GFAP protein without altering Drp1 protein expression. In the normal murine retina, Mdivi-1 primarily localizes to the inner plexiform layer, ganglion cell layer, outer plexiform layer, and inner nuclear layer. Early in the development of the ischemic murine retina, there is a marked increase in the protein expression of Mdivi-1 and glial fibrillary acidic protein (GFAP). Mdivi-1 inhibits apoptosis in the ischemic retina and significantly increases the survival rate of retinal ganglion cells (RGC) two weeks post-ischemia.

Mdivi-1 inhibits the ATPase activity and self-assembly of Dnm1 by inducing a conformational change (IC50<10 μM). It effectively suppresses C8-Bid and STS-induced mitochondrial outer membrane permeabilization (MOMP) in HeLa cells and extracellular mouse liver mitochondria. Mdivi-1 blocks the divisionof Dynamin-related GTPases, yeast Dnm1, and human Drp1, facilitating efficient and reversible mitochondrial fusion into a net-like structure. Intracellularly, it prevents apoptosis by inhibiting mitochondrial outer membrane permeabilization. Mdivi-1 represents a potential therapeutic class for treating stroke, myocardial infarction, and neurodegenerative diseases.

All GTPase assay reactions are started in a 200 μL volume, of which 150 μL is placed into the well of a 96-well plate. Depletion of NADH, as monitored by reading the A340 of the reaction, is measured every 20 s for a total of 40 min using a SpectraMAX 250 96-well plate reader. Spectrophotometric data are transferred to Excel and the measured steady state depletion of NADH over time is converted to protein activity.

Mdivi-1 is dissolved in DMSO. YPGlycerol plates are topped with 10 mL YPGlycerol containing 1% low melt agar and 75 μM mdivi-1, and cells are spotted 12 hours later using a 48 well pinning device. After pinning cells, plates are incubated at 24°C or 37°C and imaged using an Eagle Eye II imaging system.