Hydrogen peroxide-mediated protein oxidation in young and old human MRC-5 fibroblasts.

It is suggested that the aging process is dependent on the action of free radicals. One of the highlights of age-related changes of cellular metabolism is the accumulation of oxidized proteins. The present investigation was undertaken to reveal the proliferation-related changes in the protein oxidation and proteasome activity during and after an acute oxidative stress. It could be demonstrated that the activity of the cytosolic proteasomal system declines during proliferative senescence of human MRC-5 fibroblasts and is not able to remove oxidized proteins in old cells efficiently. Whereas in young cells removal of oxidized proteins was accompanied by an increase in the overall protein turnover, this increase in protein turnover could not be seen in old MRC-5 fibroblasts. Therefore, our studies demonstrate that old fibroblasts are much more vulnerable to the accumulation of oxidized proteins after oxidative stress and are not able to remove these oxidized proteins as efficiently as young fibroblasts.

[1]  T. Reinheckel,et al.  Degradation of Oxidized Proteins in K562 Human Hematopoietic Cells by Proteasome* , 1996, The Journal of Biological Chemistry.

[2]  P. Starke-Reed,et al.  Protein oxidation and proteolysis during aging and oxidative stress. , 1989, Archives of biochemistry and biophysics.

[3]  G. Saretzki,et al.  Accelerated telomere shortening in fibroblasts after extended periods of confluency. , 1998, Free radical biology & medicine.

[4]  T. Reinheckel,et al.  Degradation of oxidized proteins in mammalian cells , 1997, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[5]  A. Goldberg,et al.  Inhibitors of the proteasome block the degradation of most cell proteins and the generation of peptides presented on MHC class I molecules , 1994, Cell.

[6]  L. Tian,et al.  Alterations of antioxidant enzymes and oxidative damage to macromolecules in different organs of rats during aging. , 1998, Free radical biology & medicine.

[7]  K. Davies,et al.  Hydrophobicity as the signal for selective degradation of hydroxyl radical-modified hemoglobin by the multicatalytic proteinase complex, proteasome. , 1993, The Journal of biological chemistry.

[8]  E. Stadtman,et al.  Oxidation of free amino acids and amino acid residues in proteins by radiolysis and by metal-catalyzed reactions. , 1993, Annual review of biochemistry.

[9]  D. Yin.  Lipofuscin-like fluorophores can result from reactions between oxidized ascorbic acid and glutamine. Carbonyl-protein cross-linking may represent a common reaction in oxygen radical and glycosylation-related ageing processes , 1992, Mechanisms of Ageing and Development.

[10]  C. Harley,et al.  Telomeres shorten during ageing of human fibroblasts , 1990, Nature.

[11]  T. Reinheckel,et al.  Proteolysis in Cultured Liver Epithelial Cells during Oxidative Stress , 1995, The Journal of Biological Chemistry.

[12]  B. Ames,et al.  The free radical theory of aging matures. , 1998, Physiological reviews.

[13]  C. Winterbourn,et al.  Protein carbonyl measurement by a sensitive ELISA method. , 1997, Free radical biology & medicine.

[14]  L. Hayflick.  THE LIMITED IN VITRO LIFETIME OF HUMAN DIPLOID CELL STRAINS. , 1965, Experimental cell research.

[15]  K. Davies,et al.  Exposure of hydrophobic moieties promotes the selective degradation of hydrogen peroxide-modified hemoglobin by the multicatalytic proteinase complex, proteasome. , 1994, Archives of biochemistry and biophysics.

[16]  T. Grune,et al.  Proteasome‐dependent degradation of oxidized proteins in MRC‐5 fibroblasts , 1998, FEBS letters.

[17]  D. Yin,et al.  Biochemical basis of lipofuscin, ceroid, and age pigment-like fluorophores. , 1996, Free radical biology & medicine.