Fig. 3. Apoptosis was activated in proximal tubules and PBMCs of DKDs. (A and B) TUNEL procedure indicated an increase in apoptotic cells in renal tubules in DKDs compared to HCs. ×400 magnification. (C-F) The expression levels of Bax and Cytochrome c were both significantly up-regulated in renal tubules in DKDs compared to HCs. ×400 magnification. (G and H) Flow cytometric analysis showed increased apoptotic PBMCs from DKDs (n=14) compared to HCs (n=9) and DCs (n=19). (I) Correlation analysis revealed apoptotic PBMCs was positively correlated with RBP /Cr ratio. r, correlation coefficient; RBP, retinol-binding protein; Cr, creatinine; HC, healthy control; DC, diabetic control; DKD, diabetic kidney disease; Cyt.C, Cytochrome c.