HG predisposes HGEC to apoptosis.

<p>Treatment of HGEC with DTT for 24 h results in increased PARP and Caspase-3 cleavage, a response that occurs in a greater extent in adherent 25 mmol/L glucose-culture cells than in control (5 mmol/L glucose-cultured cells) (A; Western blot image and densitometric analysis; FL-floating cells, AT-attached cells). Increased apoptosis is further confirmed by DNA fragmentation analysis of the floating cells under these treatments (B). TUNEL assay shows apoptosis in HG-treated cells, in the absence of DTT, where DAPI (blue) and TUNEL (red) stain nuclei of viable and apoptotic cells, respectively (C). Data represent mean±SEM, n = 3–5, **P<0.01 vs. control (5 mmol/L glucose); ^•P<0.05, ^••P<0.01 vs. control (25 mmol/L glucose) and ^#P<0.05 vs. 5mmol/L-DTT treated cells.