Fig. 2.

Diabetic milieu induced increased mtDNA oxidative lesions but not nuclear (nuc) DNA lesions. a Representative immunofluorescence images detecting DNA 8-oxoG (green) and mitochondrial transcription factor A (mTFA; red) and DAPI in mGECs treated with NG, HG, CS, DS without or with mTEMPO for 24 h. Open arrows in A depict clusters and colocalization of 8-oxoG and TFAM. Arrows in B show mGEC nucleus with positive γ-H2AX foci. Scale = 100 μm. b Representative immunofluorescence images detecting γ-H2AX foci (green) and nuclei (DAPI blue) in mGECs treated with NG, HG, CS and DS for 24 h. Scale = 100 μm. Quantification of lesion frequencies in mtDNA and in nuclear (nuc) DNA by QPCR assay in mGECs treated 24 h with NG, HG, CS and DS (n = 3 ± s.e.m. relative amplification normalized to non-damaged NG controls; * P < 0.05 or ** P < 0.01 versus mtDNA control, #P < 0.05 versus nucDNA control). d RT-PCR quantification of transcripts for mitochondrial encoded genes; ND1 and ND4 in mGECs cultured in NG, HG, CS and DS for 24 h. Bars represent mean ± s.e.m. of 4 independent experiments; ND4 *P < 0.05 versus NG or CS controls, ND1 #P < 0.05 versus NG or CS controls