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Mitophagy of damaged mitochondria occurs locally in distal neuronal axons and requires PINK1 and Parkin.

Ashrafi G, Schlehe JS, LaVoie MJ, Schwarz TL - J. Cell Biol. (2014)

Bottom Line: In PINK1(-/-) axons, damaged mitochondria did not accumulate Parkin and failed to be engulfed in autophagosomes.Similarly, initiation of mitophagy was blocked in Parkin(-/-) axons.Local mitophagy likely provides rapid neuroprotection against oxidative stress without a requirement for retrograde transport to the soma.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 F.M. Kirby Neurobiology Center, Children's Hospital Boston, Boston, MA 02115.

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Parkin recruitment to damaged axonal mitochondria requires PINK1. (A–D) YFP-Parkin is recruited to mitochondria of PINK1+/+ (A and B) but not PINK1−/− (C and D) rat hippocampal axons depolarized with 40 µM Antimycin A (Ant A). White and cyan arrowheads denote YFP-Parkin–positive mitochondria; cyan arrowheads point to mitochondria analyzed with line scans in B and D. Orange and brown arrowheads denote corresponding points in images and line scans. (E) Frequency of Parkin recruitment in the indicated genotypes before and 15 min after Antimycin A treatment. n = 87–101 mitochondria from four microfluidic devices per genotype. *, P < 0.05. Error bars represent means ± SEM. AU, arbitrary unit. Bars, 5 µm.
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fig8: Parkin recruitment to damaged axonal mitochondria requires PINK1. (A–D) YFP-Parkin is recruited to mitochondria of PINK1+/+ (A and B) but not PINK1−/− (C and D) rat hippocampal axons depolarized with 40 µM Antimycin A (Ant A). White and cyan arrowheads denote YFP-Parkin–positive mitochondria; cyan arrowheads point to mitochondria analyzed with line scans in B and D. Orange and brown arrowheads denote corresponding points in images and line scans. (E) Frequency of Parkin recruitment in the indicated genotypes before and 15 min after Antimycin A treatment. n = 87–101 mitochondria from four microfluidic devices per genotype. *, P < 0.05. Error bars represent means ± SEM. AU, arbitrary unit. Bars, 5 µm.

Mentions: Genetic studies have indicated that PINK1 acts upstream of Parkin in the regulation of mitochondrial integrity (Clark et al., 2006; Park et al., 2006), and stabilization of PINK1 on the outer mitochondrial membrane is essential for Parkin recruitment in nonneuronal cells (Geisler et al., 2010; Narendra et al., 2010) and cell bodies of induced pluripotent stem cell–derived neurons (Seibler et al., 2011). Similarly, PINK1 is required for basal turnover of mitochondrial respiratory chain subunits in Drosophila melanogaster (Vincow et al., 2013). However, in the cell types examined so far, PINK1 undergoes continuous synthesis and rapid degradation in the absence of mitochondrial depolarization (Narendra et al., 2010). Because axonal transport can require days or weeks, it was uncertain whether this mechanism could pertain to distal axons. We therefore examined whether PINK1 is required for recruitment of Parkin and autophagosome membranes to axonal mitochondria. Axons of hippocampal neurons from PINK1+/+ and PINK1−/− rats were treated with 40 µM Antimycin A in the perfusion chamber. In PINK1+/+ axons, the percentage of YFP-Parkin–positive mitochondria increased from 16 to 48% after 20 min (P < 0.05; Fig. 8, A, B, and E). In contrast, YFP-Parkin failed to accumulate on Antimycin A–treated mitochondria of PINK1−/− axons (9% before and 12% after; P = 0.5; Fig. 8, C–E).


Mitophagy of damaged mitochondria occurs locally in distal neuronal axons and requires PINK1 and Parkin.

Ashrafi G, Schlehe JS, LaVoie MJ, Schwarz TL - J. Cell Biol. (2014)

Parkin recruitment to damaged axonal mitochondria requires PINK1. (A–D) YFP-Parkin is recruited to mitochondria of PINK1+/+ (A and B) but not PINK1−/− (C and D) rat hippocampal axons depolarized with 40 µM Antimycin A (Ant A). White and cyan arrowheads denote YFP-Parkin–positive mitochondria; cyan arrowheads point to mitochondria analyzed with line scans in B and D. Orange and brown arrowheads denote corresponding points in images and line scans. (E) Frequency of Parkin recruitment in the indicated genotypes before and 15 min after Antimycin A treatment. n = 87–101 mitochondria from four microfluidic devices per genotype. *, P < 0.05. Error bars represent means ± SEM. AU, arbitrary unit. Bars, 5 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4151150&req=5

fig8: Parkin recruitment to damaged axonal mitochondria requires PINK1. (A–D) YFP-Parkin is recruited to mitochondria of PINK1+/+ (A and B) but not PINK1−/− (C and D) rat hippocampal axons depolarized with 40 µM Antimycin A (Ant A). White and cyan arrowheads denote YFP-Parkin–positive mitochondria; cyan arrowheads point to mitochondria analyzed with line scans in B and D. Orange and brown arrowheads denote corresponding points in images and line scans. (E) Frequency of Parkin recruitment in the indicated genotypes before and 15 min after Antimycin A treatment. n = 87–101 mitochondria from four microfluidic devices per genotype. *, P < 0.05. Error bars represent means ± SEM. AU, arbitrary unit. Bars, 5 µm.
Mentions: Genetic studies have indicated that PINK1 acts upstream of Parkin in the regulation of mitochondrial integrity (Clark et al., 2006; Park et al., 2006), and stabilization of PINK1 on the outer mitochondrial membrane is essential for Parkin recruitment in nonneuronal cells (Geisler et al., 2010; Narendra et al., 2010) and cell bodies of induced pluripotent stem cell–derived neurons (Seibler et al., 2011). Similarly, PINK1 is required for basal turnover of mitochondrial respiratory chain subunits in Drosophila melanogaster (Vincow et al., 2013). However, in the cell types examined so far, PINK1 undergoes continuous synthesis and rapid degradation in the absence of mitochondrial depolarization (Narendra et al., 2010). Because axonal transport can require days or weeks, it was uncertain whether this mechanism could pertain to distal axons. We therefore examined whether PINK1 is required for recruitment of Parkin and autophagosome membranes to axonal mitochondria. Axons of hippocampal neurons from PINK1+/+ and PINK1−/− rats were treated with 40 µM Antimycin A in the perfusion chamber. In PINK1+/+ axons, the percentage of YFP-Parkin–positive mitochondria increased from 16 to 48% after 20 min (P < 0.05; Fig. 8, A, B, and E). In contrast, YFP-Parkin failed to accumulate on Antimycin A–treated mitochondria of PINK1−/− axons (9% before and 12% after; P = 0.5; Fig. 8, C–E).

Bottom Line: In PINK1(-/-) axons, damaged mitochondria did not accumulate Parkin and failed to be engulfed in autophagosomes.Similarly, initiation of mitophagy was blocked in Parkin(-/-) axons.Local mitophagy likely provides rapid neuroprotection against oxidative stress without a requirement for retrograde transport to the soma.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 F.M. Kirby Neurobiology Center, Children's Hospital Boston, Boston, MA 02115.

Show MeSH
Related in: MedlinePlus