If you’re like me, you look forward to summer’s juicy blueberries. You’ll sprinkle or mix them into everything you eat, and sneak a big handful every time you open your fridge. You tell yourself that it’s all for the antioxidants. Just make a bigger rationalization leap and say you’re helping blueberries fight alongside dividing mitochondria to protect us from the evils of oxidative damage.
Mitochondria are the cell’s main source of energy, and without their dynamic dividing and fusing a cell can suffer. Neurological diseases such as Alzheimer’s, Parkinson’s, and Huntington’s are all associated with defects in mitochondrial division and fusion. A recent paper describes how mitochondrial division helps to protect neurons from oxidative damage, and in turn protects them from neurodegeneration. Kageyama and colleagues looked at postmitotic neurons in mice lacking Drp1, a protein that mediates mitochondrial division. In these neurons lacking Drp1, mitochondria extended into large tubules because of excess fusion, and showed an accumulation of oxidative damage and eventual neurodegeneration. This cell death could be reversed after application of antioxidants. The images above show Purkinje neurons in brain sections from 1, 3, and 6 month old mice (boxed areas show magnified images). Compared with control brain sections (top), Purkinje neurons lacking Drp1 (bottom) experienced dramatic neurodegeneration (90% of cells lost by 6 months).
Kageyama, Y., Zhang, Z., Roda, R., Fukaya, M., Wakabayashi, J., Wakabayashi, N., Kensler, T., Reddy, P., Iijima, M., & Sesaki, H. (2012). Mitochondrial division ensures the survival of postmitotic neurons by suppressing oxidative damage originally published in the Journal of Cell Biology, 197 (4), 535-551 DOI: 10.1083/jcb.201110034