The Vitamin A Derivative All-Trans Retinoic Acid Repairs Amyloid-β-Induced Double-Strand Breaks in Neural Cells and in the Murine Neocortex
RA repairs Aβ-induced DSBs in SH-SY5Y and astrocytic DI TNC1 cells. (a) Representative pictures of comets with various tail lengths of SH-SY5Y cells or of (b) DI TNC1 cells following 30 min RA (5 μM) and/or 30 min Aβ (20 μM) treatments. Ø = without treatment for 30 min; scale bar: 200 μm. (c) Box plots of mean comet tail lengths of SH-SY5Y cells (number of cells measured: ) and of (d) DI TNC1 cells (). ANOVA with Bonferroni correction: ; ns = not significant. (e) Agarose gel electrophoresis showing comet tails of about 1 × 103 lysed SH-SY5Y cells per well treated with RA (5 μM) and/or Aβ (20 μM). Each treatment was carried out twice. A 1 kb ladder (Invitrogen) was used. (f) Graphical representation of mean optical DNA intensities for each duplicated treatment in (e). It shows that RA decreases the amount of Aβ-induced DSBs and corroborates Fig. (c). The DNA intensities were measured for 1 kb to about 20 kb DNA.