Research Paper Volume 12, Issue 1 pp 593—610

Attenuation of diabetic kidney injury in DPP4-deficient rats; role of GLP-1 on the suppression of AGE formation by inducing glyoxalase 1

Figure 6. Ex-4 treatment reduces MGO-induced AGEs formation and RAGE expression by upregulating GLO-1 enzyme and recovers the decrease in MGO–induced GLO-1 expression in rat mesangial cells. Rat mesangial cells were treated either with 1 mM MGO, 10 nM Ex-4, or both for 10 h after synchronization with 1% fetal bovine serum for 13-16 h. AGEs formation was measured as described in Materials and Methods. (A) AGEs formation, (B) RAGE protein level with representative blot, (C) GLO-1 mRNA level, and (D) GLO-1 protein level with a representative blot (E) Nrf-2 protein level with a representative blot in total protein extracts, (F) Representative blot of Nrf-2 protein in cytosol and nuclear fractions in rat mesangial cells. 1: CON; 2: MGO; 3: Ex-4; 4: MGO + Ex-4 (G) Nrf-2 protein level in cytosol fraction. (H) Nrf-2 protein level in nuclear fraction. Data are shown as the means ± SEM. *p < 0.05 and CON, #p < 0.05 and MGO, n = 4–7.