Parkin Protects against Oxygen-Glucose Deprivation/Reperfusion Insult by Promoting Drp1 Degradation

Figure 3

The effect of Drp1 knockdown on mitochondria morphology, function, and apoptosis in N2a cells exposed to OGDR insult. After being transfected with siRNA against Drp1, cells were treated with OGD 4 h plus 12 h reperfusion. The experiment was repeated independently for at least three times. (a) Digital photomicrograph under fluorescent illumination showing the morphology of mitochondria was detected using Tom20 staining. The confocal images and the enlarged section of the confocal images are displayed. Most of N2a cells displayed typical tubular and long mitochondria in normal condition or after 4 h OGD. Fragmented mitochondria were evident in N2a cells exposed to 4 h OGD plus 12 h reperfusion. Transfection with siRNA against Drp1 significantly attenuated OGDR induced fragmentation of mitochondria. (b) Representative immunoblots of Drp1 showed knockdown of Drp1 by the specific Drp1 siRNA. (c) Quantitation (mean ± SEM) of A from three independent experiments. (d, e) Knockdown of Drp1 in vitro reduced OGDR induced apoptosis. (f, g) Cytochrome c oxidase and mitochondrial ATP synthase activity in N2a cells with or without Drp1 depletion after OGDR insult. Drp1 protein knockdown significantly improved cytochrome c oxidase activity and mitochondrial ATP synthase activity after OGDR insult. Values are expressed as mean ± SEM. and compared to control.

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