Oxidative stress during aging

The problem is that oxidative stress is a necessary part of our response to infection without it, we are unable to mount a genetic defence against pathogens. Oxidative stress activates transcription factors such as NFkB, which coordinate the broader genetic response promoting inflammation and stress resistance.5 Unfortunately, the rise in oxidative stress during ageing also activates NFkB. The pressure to eliminate infection in youth is... 

In addition, there is experimental evidence showing that mitochondrial cardiolipin content markedly decreases following ischemia and reperfusion injury due to cardiolipin peroxidation (Soussi et al., 1990) and that a decrease in the mitochondrial phospholipid cardiolipin occurred in aged rat hearts (Pepe, 2000). These decreases may he attrihutahle to the hydroperoxide-formation of cardiolipin after exposure to intense or repeated oxidative stress during disease state or normal aging, respectively. 

The repair of oxidative damage may be incomplete. Only reduction of the d-diastereomer of calmodulin-bound methionine sulfoxide (L-Met-D-SO) by methionine sulfoxide reductase was demonstrated, while in the cells both d- and l-steoreoisomers are formed. Such incomplete, diastereoselective repair by methionine sulfoxide reductase contributes to the accumulation of methionine sulfoxide residues during oxidative stress and aging in vivo (S24). 

Breusing, N. and Grune, T. 2008. Regulation of proteasome-mediated protein degradation during oxidative stress and aging. Biol Chem. 389, 203-9. 

The turnover rates of GSH and the activity of GSH synthetase during oxidative stress induced by butylhydroperoxide in young and mature animals have been measured. These studies have found that defense mechanisms against oxidative stress in the brain differ with age. Young people can increase the cellular availability of GSH, whereas older people can increase GSH synthetase activity during oxidative stress. These differences make older people more susceptible to brain oxidative damage. 

Increased levels of ROS due to oxidative stress have been consistently found in cardiovascular diseases as atherosclerosis or hypertension [18]. There is certain evidence that the free radicals involved in Parkinson s disease are mainly due to the production of increased levels of free radicals during oxidative metabolism of dopamine [19]. Oxidative stress, manifested by protein oxidation and lipid peroxidation (LP), among other alterations, is a characteristic of Alzheimer s disease [20] and in the pathogenesis of diabetes related complications. Treatment with antioxidants seemed to be a promising therapeutic option for these diseases [21], The inflammatory nature of rheumatoid arthritis implies that a state of oxidative stress may also exist in this disease [22,23]. Also, free radicals have a certain role in Huntington s disease [24,25], age related degeneration [26], and some autoimmune disorders [27],... 

Oxidative stress can be caused by a wide variety of factors, including inflammatory responses to infections or immune activation, exposure to heavy metals or toxic substances (Carpenter et al., 2002), and oxidative stress increases during the natural course of aging (Junqueira et al., 2007). When oxidative stress is induced by environmental exposures it represents a significant component of the toxicity syndrome, and most xenobiotics share the ability to cause oxidative stress. As a consequence, the effects of multiple exposures are additive at the level of oxidative stress. Metabolic changes associated with oxidative stress can be considered to be adaptive responses that increase prospects for survival during these stressful episodes. 

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