Oxidative stress mediates tau-induced neurodegeneration in Drosophila
J. Clin. Invest. Dora Dias-Santagata, et al. 117:236 doi:10.1172/JCI28769 [Go to this article.]

Figure 2
Downregulation of Sod2 or of Trxr antioxidant activities increases neuronal cell death in a Drosophila tauopathy model. (A–D) TUNEL assay in 10-day-old transgenic fly brains. Apoptotic cells, absent in control animals (A), were identified by TUNEL staining (arrows) in the brains of tau^R406W transgenic flies (B) and were found to be more abundant in tau^R406W flies heterozygous for Trxr^Δ1 (C) and for Sod2ⁿ²⁸³ (D). Scale bar: 10 μm. (E) Neurodegeneration was significantly enhanced by partial inactivation of Trxr (***P < 0.001) and Sod2 (***P < 0.001) activities. The number of TUNEL-positive cells in the brains of 10-day-old tau^R406W-expressing flies was compared with that in age-matched controls, in Sod2ⁿ²⁸³ and Trxr^Δ1 heterozygous animals, and in tau^R406W flies heterozygous for either Sod2ⁿ²⁸³ or Trxr^Δ1. Data points represent the mean ± SEM. (F–K) Tau-induced toxicity was associated with neuronal cell death. TUNEL-positive cells (green fluorescence) were found to coexpress the neuronal cell marker elav (red fluorescence) (F–H) and did not colocalize with repo-positive glial cells (red fluorescence) (I–K). Arrowheads mark the location of TUNEL-positive cells. Scale bars: 5 μm.