Protein Carbonyl Level Causes Oxidative Protein Damage In Diabetics

Plasma carbonyl level is a relevant marker of protein oxidation in both diabetes mellitus and diabetic hemodialysis patients.

Oxidative stress is considered to be a unifying link between diabetes mellitus (DM) and its complications, including nephropathy. There is sufficient evidence on increased production of oxidants and decreased level of antioxidants in diabetic patients. The dialysis procedure contributes to oxidative stress. An increase in oxidative stress may contribute to the development of oxidative protein damage in diabetic patients.

A new study, which appears in the May-June issue of Journal of Diabetes and its Complications was conducted to reveal the effects of diabetes and hemodialysis (HD) on oxidative modifications of plasma proteins.

Researchers from the Department of Biochemistry and Nephrology, Medical Faculty, Akdeniz measured reactive carbonyl derivates (PCO), protein thiol (P-SH), and reduced glutathione (GSH) levels in Type 2 diabetic (DM) and diabetic hemodialysed patients (DHD) and in healthy control participants.

It was found that protein carbonyl (PCO) content increased significantly in all patient groups relative to the controls. The dialysis procedure caused an additional increase in PCO levels in DHD patients before and after dialysis compared with the level in DM patients. There was a significant decrease in P-SH levels in DHD patients compared with the level in healthy participants and DM patients. There was no significant difference in the whole blood GSH levels between the DM patients and control participants. It was significantly higher in DHD patients in comparison to the DM patients.

Data from this study confirm that plasma carbonyl level is a relevant marker of protein oxidation in both DM and diabetic HD patients. Increased ROS may interact with proteins, leading to oxidative modifications of proteins.

The authors conclude that PCO level increases in DM patients, and this increase is more profound in DHD patients, indicating that both diabetes and dialysis contribute to increased protein oxidation. The low P-SH level in DHD patients, but not in DM patients, suggests that dialysis is responsible for this decrease. Thus, the oxidative damage to plasma proteins is reflected by an increase in the levels of plasma PCO, and a decrease in the levels of plasma P-SH in DHD patients and P-SH groups is efficient antioxidant.

The authors propose plasma PCO derivate as a novel specific marker for oxidative protein damage.

Medindia on Diabetes:

Diabetes is a group of diseases with one thing in common - a problem with insulin. The problem could be that your body doesn't make any insulin, doesn't make enough insulin or doesn't use insulin properly.