Regulation of Antioxidant Enzymes

Harris, Edward D.

doi:10.1093/jn/122.suppl_3.625

Cited by 141 publications

(159 citation statements)

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“…As described above, both the redox state of the cell itself and cytokines (mainly IL-1 and TNF-cx) are involved in the regulation of the gene encoding for the MnSOD (Hassan, 1988;Harris, 1992;Wong, 1995), and autocrine and/or paracrine secretion of these cytokines by glioblastomas or by the brain tissue surrounding the tumour was reported (Nitta et al, 1994). Immunoreactive MnSOD We observed low levels of immunoreactive MnSOD in some ( 30%) of the glioblastomas that we studied.…”

Section: Discussionmentioning

confidence: 58%

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The level of MnSOD is directly correlated with grade of brain tumours of neuroepithelial origin

Landriscina

Remiddi²,

Ria³

et al. 1996

Br J Cancer

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Summary The oxy-radical scavenger enzyme manganese superoxide dismutase (MnSOD) may act in the capacity of a tumour-suppressor gene. To address the issue of its role in tumour transformation and progression in vivo, we evaluated the content of this enzyme in 33 brain tumours of neuroepithelial origin with different degrees of differentiation (WHO grade II-IV) by means of Western blot and immunohistology. Our results show that immunoreactive MnSOD increases in a direct relationship with tumour grade and is therefore inversely correlated with differentiation. The increase is induced at a pretranscriptional level and is apparently specific to brain tumours of neuroepithelial origin. Approximately 30% of grade IV tumours display low levels of MnSOD content, and preoperative radiotherapy and brachytherapy result in low amounts of enzyme. Based upon these observations, we suggest that MnSOD cannot be considered a classical tumour-suppressor gene.

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Section: Discussionmentioning

confidence: 58%

“…While cytosolic CuZnSOD is a constitutive enzyme, MnSOD is an inducible protein, and the expression of its gene is regulated by the redox state of the cell and by cytokines, among which a dominant role is played by IL-1 and TNF-oa (Hassan, 1988;Harris, 1992;Wong, 1995).…”

mentioning

confidence: 99%

The level of MnSOD is directly correlated with grade of brain tumours of neuroepithelial origin

Landriscina

Remiddi²,

Ria³

et al. 1996

Br J Cancer

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“…Mn-SOD, localized in the mitochondria matrix, has an essential function reducing the cellular concentraton of superoxide radicals during both normal oxidative metabolism and periods of oxidative stress. The important role of Mn-SOD is demonstrated by the large variety of factors which regulate its expression (development, differentiation, oxidative stress, xenobiotics, cytokines; as reviewed by Harris, 1992). Most of these factors induce some modifications of the intracellular levels of reactive oxygen species.…”

Section: Discussionmentioning

confidence: 99%

Changes in superoxide dismutase mRNA expression by streptozotocin‐induced diabetes

Kamata

Kobayashi

1996

British J Pharmacology

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Experiments were designed to investigate the involvement of superoxide anions in the attenuated endothelium‐dependent relaxation of the rat aorta from streptozotocin (STZ)‐induced diabetic rats. The endothelium‐dependent relaxation responses to acetylcholine (ACh, 10−7 m) in helical strips of the aorta precontracted with noradrenaline (NA, 5 × 10−8∼3 × 10−7 m) were significantly decreased in STZ‐induced diabetic rats. The recovery phase of the relaxation after single administration of ACh in the STZ‐induced diabetic rats was more rapid than those in control vessels. Preincubation of aortic strips with superoxide dismutase (SOD, 60 u ml−1) normalized the recovery phase of the relaxation of diabetic aorta after single administration of ACh, whereas catalase (150 u ml−1) or indomethacin (10−5 m) had no effects on the relaxation. SOD (180 u ml−1) caused relaxation in NA precontracted aortic strips and the degree of the SOD‐induced relaxation was significantly greater in diabetic aorta as compared with age‐matched control vessels. When the changes in mRNA expressions of Mn‐SOD or Cu‐Zn‐SOD were observed, Mn‐SOD mRNA expression was markedly decreased, and Cu‐Zn‐SOD was slightly decreased in diabetic aorta. These results suggest that the rapid destruction of NO by superoxide anions may occur in the STZ‐induced diabetic rats, and this may be due to a decrease in mRNA expression of Mn‐SOD or Cu‐Zn‐SOD.

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“…Thus, the extent of oxidative damage during physical exercise is determined not only by the level of free radical generation, but also by the defense capacity of antioxidants. Available data suggest that each of the antioxidant systems may have a different response to acute and chronic exercise depending upon their biochemical and molecular mechanism of regulation (53). In recent years, there is a general awareness of the importance of antioxidants, but insufficient knowledge often leads to the false conclusion that physically active people need antioxidant supplementation.…”

Section: Regulation and Adaptation Of Antioxidant Systemsmentioning

confidence: 99%

“…There is still insufficient knowledge about either the kinetic properties or molecular regulation of these enzymes in mammalian tissues (53). In the past decade an intensive search has been conducted for the regulatory mechanism of gene expression for antioxidant enzymes in response to oxidative stress.…”

Section: Summary Of Findingsmentioning

confidence: 99%

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

Leichtweis

1997

AGE

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Strenuous exercise is characterized by increased oxygen consumption and the disturbance between intracellular pro-oxidant and antioxidant homeostasis. At lease three biochemical pathways (i.e., mitochondrial electron transport chain, xanthine oxidase, and polymorphoneutrophil) have been identified as potential sources of intracellular free radical generation during exercise. These deleterious reactive oxygen species pose a serious threat to the cellular antioxidant defense system, such as diminished reserves of antioxidant vitamins and glutathione. However, enzymatic and non-enzymatic antioxidants have demonstrated great versitility and adaptability in response to acute and chronic exercise. The delicate balance between pro-oxidants and antioxidants suggests that supplementation with antioxidants may be desirable for physically active individuals under certain physiological conditions by providing a larger protective margin.

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Regulation of Antioxidant Enzymes

Cited by 141 publications

References 1 publication

The level of MnSOD is directly correlated with grade of brain tumours of neuroepithelial origin

The level of MnSOD is directly correlated with grade of brain tumours of neuroepithelial origin

Changes in superoxide dismutase mRNA expression by streptozotocin‐induced diabetes

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

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