Hydrogen decreases athero-susceptibility in apolipoprotein B-containing lipoproteins and aorta of apolipoprotein E knockout mice

• Published in: Atherosclerosis 2012-03, Vol.221 (1), p.55-65
• Main Authors: Song, Guohua, Tian, Hua, Qin, Shucun, Sun, Xuejun, Yao, Shutong, Zong, Chuanlong, Luo, Yingying, Liu, Jia, Yu, Yang, Sang, Hui, Wang, Xinnong
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - metabolism; Aorta - drug effects; Aorta - metabolism; Aorta - pathology; Aortic Diseases - blood; Aortic Diseases - genetics; Aortic Diseases - pathology; Aortic Diseases - prevention & control; ApoB-containing lipoprotein; Apolipoproteins B - blood; Apolipoproteins B - metabolism; Apolipoproteins E - deficiency; Apolipoproteins E - genetics; Atherosclerosis; Atherosclerosis (general aspects, experimental research); Atherosclerosis - blood; Atherosclerosis - genetics; Atherosclerosis - pathology; Atherosclerosis - prevention & control; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Biological and medical sciences; Blood and lymphatic vessels; Blotting, Western; Cardiology. Vascular system; Cardiovascular; Cholesterol - blood; Diet, High-Fat; Disease Models, Animal; Diseases caused by cestodes; Echinococcoses; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation - drug effects; HDL function; Helminthic diseases; Hydrogen; Hydrogen - administration & dosage; Hydrogen - metabolism; Immunohistochemistry; Infectious diseases; Inflammation; Inflammation Mediators - blood; Injections, Intraperitoneal; Lipoproteins, HDL - blood; Liver - drug effects; Liver - metabolism; Macrophages - drug effects; Macrophages - metabolism; Male; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Knockout; Oxidation-Reduction; Parasitic diseases; Real-Time Polymerase Chain Reaction; Scavenger Receptors, Class B - genetics; Scavenger Receptors, Class B - metabolism; Sodium Chloride - administration & dosage; Sodium Chloride - metabolism; Spectrophotometry
• ISSN: 0021-9150; 1879-1484
• DOI: 10.1016/j.atherosclerosis.2011.11.043

Abstract Objective It is to characterize the underlying molecular mechanisms of the anti-atherosclerotic effects of hydrogen (dihydrogen; H2 ), a novel antioxidant. In particular, to examine the effects of hydrogen on athero-susceptibility in lipoproteins and aorta of apolipoprotein E knockout (apoE−/−) mice. Methods and results Plasma analysis by enzymatic method and spectrophotometric measurement showed that eight weeks intraperitoneally injection of hydrogen-saturated saline remarkably decreased plasma total and non-high-density lipoprotein (non-HDL) cholesterol, and malondialdehyde in apoE−/− mice fed either chow or high fat diet. Western blot analysis showed hydrogen treatment reduced the contents of apolipoprotein B (apoB), a major protein constituent of non-HDL in either plasma or hepatic tissues. Moreover, ELISA assay revealed that the production of tumor necrosis factor-α and interleukin-6 were significantly suppressed by hydrogen in RAW264.7 macrophages, after stimulation with the isolated non-HDL from treated or untreated mice. Immunohistochemistry of aortic valve sections revealed that hydrogen suppressed the expression of several proinflammatory factors and decreased vessel wall infiltration of macrophages. Besides, real-time PCR and Western blot analysis disclosed that hepatic scavenger receptor class B type I (SR-BI), ATP-binding cassette (ABC) transporters ABCG8, ABCB4, ABCB11, and macrophage SR-BI, were all induced by hydrogen treatment. Finally arterial wall lipid disposition displayed by oil red O staining was reduced significantly in aortic root and whole aorta en face in hydrogen administrated mice. In addition, hydrogen significantly improved HDL functionality in C57BL/6J mice assessed in two independent ways, namely (i) stimulation of cholesterol efflux from macrophage foam cells by measuring HDL-induced [3 H]cholesterol efflux, and (ii) protection against LDL oxidation as a measure of Cu2+ -induced TBARS formation. Conclusion These results reveal that administration of hydrogen-saturated saline decreases athero-susceptibility in apoB-containing lipoprotein and aortic atherosclerosis in apoE−/− mice and improves HDL functionality in C57BL/6J mice.