Effects of ageing on carbonyl stress and antioxidant defense in RBCs of obese Type 2 diabetic patients.
In this study we investigated the effects of ageing on the carbonyl stress (protein carbonyls and 4-hydroxy-2-nonenal groups) and glutathione antioxidant defense in red blood cells (RBCs) of obese Type 2 diabetic patients with/without hypertensive complications. To this purpose the following methods were used: spectrophotometry (protein carbonyls, glutathione and glutathione peroxidase assays), immunofluorescence (4-hydroxy-2-nonenal localization), western blotting (immunodetection of carbonylated proteins). The results showed that compared to RBCs of healthy subjects, in obese Type 2 diabetics, ageing is associated with: (i) an increase in the concentration and expression of carbonylated proteins, a marker of oxidative stress; (ii) a decrease of both non-enzymatic and enzymatic endogenous glutathione defenses; (iii) a severely disturbed oxidant/antioxidant balance when obesity was associated with hypertension. The simultaneous insults of high blood pressure, obesity, and diabetes conducted to the highest carbonyl stress, exposure of 4-hydroxy-2-nonenal Michel adducts at the outer leaflet of RBCs plasmalemma, and the lowest glutathione antioxidant potential, particularly in elderly patients. These results can explain the gradual age-dependent diminishment of the detoxification potential of RBCs that at the old age can not overcome the deleterious effects of the high systemic oxidative stress.
Constantin
Alina
A
Institute of Cellular Biology and Pathology N. Simionescu, Bucharest, 050568, Romania. alina.constantin@icbp.ro
Constantinescu
Elena
E
Dumitrescu
Madalina
M
Calin
Adina
A
Popov
Doina
D
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000975:Antioxidants / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D004910:Erythrocyte Membrane / Q000502:physiology; D004912:Erythrocytes / Q000502:physiology*; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D018384:Oxidative Stress; D012016:Reference Values
D000975:Antioxidants; D001798:Blood Proteins; D005978:Glutathione