Effects Of Advanced Glycation End Products And Drugs On The Expression Of Fractalkine

Objectives: To investigate the effects of advanced glycation end products(AGEs)on the expression of fractalkine(FKN, CX3CL1)in cultured human renal mesangial cells (HRMC), and the influence of Rosiglitazone, Irbesartan and Aminoguanidine on the FKN expression. To observe the effects of Rosiglitazone and Irbesartan on the FKN expression in renal cortex and the serum AGE-peptide(AGE-P)of diabetic rats.Methods:1. HRMC were incubated with different concentrations of AGE-bovine serum albumin (AGE-BSA)for different time, and exposed to AGE-BSA(200 mg·l-1)in presence of different concentrations of Rosiglitazone, Irbesartan and Aminoguanidine for 24 hours, respectively. 2. Type 2 diabetic rats were induced by streptozotocin and high fat diet, and then treated with or without Rosiglitazone, Irbesartan. 3. The proliferation of HRMC was estimated by MTT. The activities of SOD, CAT and the level of MDA were detected by spectrophotometry. 4. The mRNA and protein expression of FKN in HRMC were analyzed by use of RT-PCR and Westernblot respectively. The expression of FKN in renal cortex of rats was decetcted with RT-PCR and immunohistochemistry. 5. The serum AGE-P of diabetic rats was analyzed by flow injection assay.Results:1. AGE-BSA increased the proliferation rate of HRMC time- and dose- dependently. AGE-BSA decreased the activities of SOD, CAT and increased the level of MDA in supernatants of cultured HRMC(P<0.05). 2. AGE-BSA increased the expression of FKN in the level of mRNA and protein time- and dose- dependently (P<0.05). 3. The elevated expressions of FKN mRNA and protein in AGE-BSA treated HRMC were decreased by exposoure to Rosiglitazone, Irbesartan and Aminoguanidine (P<0.05). 4. The level of FKN mRNA and protein in renal cortex of diabetic rats was significantly higher than that of normal control. But that in treated groups with Rosiglitazone and Irbesartan was significantly lower than that of untreated groups (P<0.05). 5. The serum AGE-P was higher in diabetic rats than that in normal control. But that in treated groups with Rosiglitazone and Irbesartan was lower than that in untreated groups (P<0.05).Conclusions:1. AGE-BSA promotes the proliferation of HRMC. AGE-BSA increases the production of reactive oxygen species and inhibits the activities of SOD and CAT in cultured HRMC. These findings suggest that AGEs may induce the oxidative imbalance. 2. AGE-BSA upregulates the expression of FKN mRNA and protein in HRMC. The serum AGE-P and the expression of FKN in renal cortex in diabetic rats are elevated. The data indicates that FKN might mediate the role of AGEs in the development of diabetic nephropathy. 3. Rosiglitazone, Irbesartan and Aminoguanidine inhibit the upregulation of FKN in HRMC by AGE-BSA. Rosiglitazone, Irbesartan reduce the serum AGE-P and the content of FKN in renal cortex of diabetic rats. These results suggest Rosiglitazone and Irbesartan might play their role of reno-protection via supression of AGEs and FKN.