title: Determination of HEL (Hexanoyl-lysine adduct): a novel biomarker for omega-6 PUFA oxidation.
abstract: Published evidences indicate that reactive oxygen species (ROS) can induce lipid peroxidation, which plays important role in the pathophysiology of numerous diseases including atherosclerosis, diabetes, cancer and aging process. Monitoring of oxidative modification or oxidative damages of biomolecules may therefore be essential for the understanding of aging, and age-related diseases. N-epsilon-Hexanoyl-lysine (HEL) is a novel lipid peroxidation biomarker which is derived from the oxidation of omega-6 unsaturated fatty acid. In this chapter, development of HEL ELISA and its applications are reported. Assay range of HEL ELISA was 2-700 nmol/L, and showed good linearity and reproducibility. Accuracy of this assay was validated by recovery test and absorption test. HEL concentration in human urine was 22.9 ± 15.4 nmol/L and it was suggested that HEL exists as low molecular substances, in a free or in the peptide-attached form. In contrast with the urine sample, serum HEL was suggested to exist in the protein-attached form, and hydrolysis by protease might be essential for the accurate measurement of HEL in protein containing samples such as serum and cultured cells. By sample pretreatment with proteases, HEL was successfully detected in oxidized LDL, oxidized serum, and rat serum. In conclusion, HEL ELISA can be applied to measure urine, serum, and other biological samples independent of the animal species, and may be useful for the assessment of omega-6 PUFA oxidation in the living bodies.
authors.affiliation: Japan Institute for the Control of Aging (JaICA), Nikken SEIL Co., Ltd., 710-1 Haruoka, Fukuroi-shi, Shizuoka, 437-0122, Japan, biotech@jaica.com.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Sakai
authors.forename: Satoko
authors.initials: S
authors.lastname: Kino
authors.forename: Aino
authors.initials: A
authors.lastname: Masuda
authors.forename: Masao
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Tairin
authors.initials: T
authors.lastname: Ochi
authors.forename: Josko
authors.initials: J
authors.lastname: Osredkar
authors.forename: Barbara
authors.initials: B
authors.lastname: Rejc
authors.forename: Ksenija
authors.initials: K
authors.lastname: Gersak
authors.forename: Narasimhan
authors.initials: N
authors.lastname: Ramarathnam
authors.forename: Yoji
authors.initials: Y
authors.lastname: Kato
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000737:chemistry / Q000378:metabolism; D043371:Fatty Acids, Omega-6 / Q000737:chemistry* / Q000652:urine; D000441:Hexanols / Q000737:chemistry* / Q000652:urine; D006801:Humans; D015227:Lipid Peroxidation; D008055:Lipids / Q000652:urine; D008077:Lipoproteins, LDL / Q000737:chemistry / Q000378:metabolism; D008239:Lysine / Q000737:chemistry* / Q000652:urine; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D051381:Rats
chemical_list: D015415:Biomarkers; D043371:Fatty Acids, Omega-6; D000441:Hexanols; D008055:Lipids; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D008239:Lysine