title: Plasma S-adenosylhomocysteine is a better biomarker of atherosclerosis than homocysteine in apolipoprotein E-deficient mice fed high dietary methionine.
abstract: Homocysteine (Hcy) and S-adenosylhomocysteine (AdoHcy) are critical intermediates of methionine metabolism. To investigate which, if either, of these compounds is more closely related to atherosclerosis, we fed 5 groups of apolipoprotein E (apoE)-deficient mice different diets for 8 wk to induce changes in their plasma Hcy and AdoHcy concentrations. These included an AIN-93G control diet (C), this C diet supplemented with methionine (M), the M diet deficient in folates, vitamin B-6, and vitamin B-12 (M-V), this M diet supplemented with these B vitamins (M+V), and a C diet deficient in B vitamins (C-V). Compared with controls, mice fed the C-V diet had a moderate elevation in their plasma total Hcy (tHcy) levels; however, their plasma AdoHcy concentration and atherosclerotic lesion areas were not different. In contrast, the mice fed the M+V diet had larger atherosclerotic lesion areas and elevated plasma AdoHcy concentrations but their plasma tHcy concentration did not differ from that of the group C mice. The plasma AdoHcy concentration and aortic sinus lesion areas were positively correlated (r = 0.866; P < 0.001). We observed a negative correlation between the plasma AdoHcy concentration and both the DNA methyltransferase activity (r = -0.792; P < 0.001) and global DNA methylation status (r = -0.824; P < 0.001) in the aortic tissue. Hence, our study suggests that plasma AdoHcy is a better biomarker of atherosclerosis than Hcy and may accelerate the development of atherosclerotic lesions in apoE-deficient mice that have been fed a high methionine diet. The mechanisms underlying this effect may be related to the AdoHcy-mediated inhibition of DNA methylation in the aortic tissue.
authors.affiliation: Department of Nutrition, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou 510080, PR China.
authors.forename: Chi
authors.initials: C
authors.lastname: Liu
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Honghui
authors.initials: H
authors.lastname: Guo
authors.forename: Min
authors.initials: M
authors.lastname: Xia
authors.forename: Qin
authors.initials: Q
authors.lastname: Yuan
authors.forename: Yan
authors.initials: Y
authors.lastname: Hu
authors.forename: Huilian
authors.initials: H
authors.lastname: Zhu
authors.forename: Mengjun
authors.initials: M
authors.lastname: Hou
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Tang
authors.forename: Wenhua
authors.initials: W
authors.lastname: Ling
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency* / Q000235:genetics*; D050197:Atherosclerosis / Q000097:blood* / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D019175:DNA Methylation; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005492:Folic Acid / Q000097:blood / Q000494:pharmacology; D006710:Homocysteine / Q000097:blood*; D008297:Male; D008715:Methionine / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D012435:S-Adenosylhomocysteine / Q000097:blood*; D014805:Vitamin B 12 / Q000097:blood / Q000494:pharmacology; D025101:Vitamin B 6 / Q000097:blood / Q000494:pharmacology
chemical_list: D001057:Apolipoproteins E; D015415:Biomarkers; D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D012435:S-Adenosylhomocysteine; D008715:Methionine; D014805:Vitamin B 12