Fig. 4

Mitochondria promote the expression of ATF3 through ROS induced DSBs. Four days after constructing SNI models and administering mitochondrial injection therapy, the DRGs were surgically extracted and sectioned. The levels of reactive oxygen species (ROS) in the DRGs were evaluated using Hydrocyanine-Cy3 staining and relative fluorescence quantification among the Sham, SNI, SNI with mitochondrial injection therapy (SNI + Mito), and SNI with mitochondrial injection and oxidant scavenger N-acetylcysteine (NAC) treatment (SNI + Mito + NAC) groups. (A) Representative Hydrocyanine-Cy3 staining images of DRG tissue from the Sham, SNI, SNI + Mito and SNI + Mito + NAC groups (left). Relative quantification of Hydrocyanine-Cy3 fluorescence intensities of the above 4 groups. The levels of DNA double strand breaks and ATF3 protein expression in DRGs from the above 4 groups were detect by Western blot. (B) Western blot of protein expression levels of DSB markers of γ-H2AX and 53BP1, and ATF3 in DRGs from Sham, SNI, SNI + Mito and SNI + Mito + NAC groups (left). Densitometric analysis of the protein expression of γ-H2AX, 53BP1, and ATF3 among the above 4 groups (right). Protein expression was normalized against β-actin. Data represent means ± SD. Statistically significant differences are indicated; n = 3; *P < 0.05, vs. Control