title: Increased protein oxidation and loss of protein-bound sialic acid in hepatic tissues of D-galactose induced aged rats.
abstract: A redox basis of the increased oxidative protein damage and free radical-mediated desialylation have not been fully elucidated in aging. It is well known that the incidence of several liver diseases increase with age. This original research focuses on protein oxidation mechanisms and protein-bound sialic acid levels in liver tissue of the mimetic aging rats. Injection of D-galactose (60 mg/kg/day) for six weeks to male Sprague-Dawley rats (20-week-old) used to establish mimetic aging model. We investigated the tissue levels of various protein oxidation markers such as protein carbonyl groups, suitable advanced oxidation protein products and protein thiol groups. Our study also covered protein-bound sialic acid in liver tissue of D-galactose-induced aging rats. PCO (Protein Carbonyl Groups), P-OOH (Protein Hydroperoxides) and AOPP (Advanced Oxidation Protein Products) levels in aging rats were significantly higher compared to young control groups. On the other hand, P-SH (Protein Thiol Groups) levels were not found to be different between two groups. SA (Sialic Acid) levels in D-galactose-induced aging rats were significantly lower compared to control groups. Our results demonstrated greater susceptibility to hepatic oxidative protein damage and desialylation of hepatocellular proteins in Dgalactose- induced aging rats. These molecular mechanisms may be operative in the many age-related liver diseases, which are pertinent to increased oxidative stress and altered redox homeostasis.
authors.affiliation: Department of Biochemistry, Istanbul University, Fatih, Istanbul, Turkey. cakatay@yahoo.com
authors.forename: Ufuk
authors.initials: U
authors.lastname: Cakatay
authors.forename: Seval
authors.initials: S
authors.lastname: Aydın
authors.forename: Pınar
authors.initials: P
authors.lastname: Atukeren
authors.forename: Karolin
authors.initials: K
authors.lastname: Yanar
authors.forename: Mustafa E
authors.initials: ME
authors.lastname: Sitar
authors.forename: Enis
authors.initials: E
authors.lastname: Dalo
authors.forename: Ezel
authors.initials: E
authors.lastname: Uslu
mesh_terms: D062107:Advanced Oxidation Protein Products / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D005690:Galactose / Q000009:adverse effects*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D050050:Protein Carbonylation; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D062107:Advanced Oxidation Protein Products; D011506:Proteins; D013438:Sulfhydryl Compounds; D006861:Hydrogen Peroxide; D019158:N-Acetylneuraminic Acid; D005690:Galactose