Advanced glycation end products, oxidative stress and metalloproteinases are altered in the cerebral microvasculature during aging.
Biological aging is associated with an increased incidence of cerebrovascular disease. Recent findings indicate that oxidative stress promoting age-related changes of cerebral circulation are involved in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease. The aim of this study was to evaluate the contribution of cerebral microvessels to the oxidative stress during brain aging, by: (i) assessment of precursors for advanced glycation end products (AGE) formation, (ii) activities of antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione disulfide reductase (GR), and (iii) the activities of metalloproteinases (MMPs), MMP-2 and MMP-9, involved in synaptogenesis and memory consolidation. The experiments were performed on two groups of male Wistar rats: 15 young (3-6 months old) and 15 aged (18-24 months old) animals. The cerebral microvessels were isolated by mechanical homogenization, the concentration of protein carbonyls and the activity of antioxidant enzymes were evaluated by spectrophotometry, and gelatin SDS-PAGE zymography was employed to evaluate MMP-2 and MMP-9 activities. The results showed that, by comparison with young rats, aged brain microvessels contain: (i) approximately 106 % increase of protein carbonyls production; (ii) approximately 68% higher GPx activity, unmodified activities of SOD and GR; (iii) approximately 30% diminishment in MMP-2 activity, and the specific occurrence of MMP-9 enzyme. The data suggest that the age-related changes of microvessels could increase the propensity for cerebral diseases and might represent, at least in part, a prerequisite for the deterioration of mental and physical status in the elderly.
Department of Cerebrovascular Dysfunctions, Institute of Cellular Biology and Pathology N Simionescu, Bucharest, Romania.
Florentina
F
Safciuc
Alina
A
Constantin
Adrian
A
Manea
Manuela
M
Nicolae
Doina
D
Popov
Monica
M
Raicu
Dorin
D
Alexandru
Elena
E
Constantinescu
D000375:Aging / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001921:Brain / Q000254:growth & development; D002196:Capillaries / Q000201:enzymology / Q000378:metabolism / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D007202:Indicators and Reagents; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D045726:Metalloproteases / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology*; D050050:Protein Carbonylation; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000502:physiology
D000975:Antioxidants; D017127:Glycation End Products, Advanced; D007202:Indicators and Reagents; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D045726:Metalloproteases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9