title: Rac1 is a possible link between obesity and oxidative stress in Chinese overweight adolescents.
abstract: Enhanced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in the monocytes occurred in metabolic syndrome, hypertension, diabetes and obese patients in adults. However, whether NADPH oxidase is involved in the oxidative stress of overweight adolescents without comorbidities is still unclear. This study aimed to identify whether and how NADPH oxidase plays a crucial role in overweight adolescents. The study was performed in 93 overweight adolescents and 31 normal weight controls. Moreover, 87 overweight adolescents were enrolled in weight-loss program. Demographics characteristics, anthropometrics, composition and clinical characteristics were analyzed. Oxidative stress indexes including the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in plasma and the expression of NADPH oxidase in the monocytes were examined. Overweight adolescents showed a higher oxidative stress state, as indicated by decreased SOD activity and elevated MDA level (P < 0.01). Furthermore, increased NADPH oxidase activity in the monocytes was accompanied by Rac1 upregulation. A significant positive bivariate correlation was found between Rac1 expression and MDA (r = 0.289). There also was a significant positive bivariate correlation between Rac1 expression and obesity-related indexes including BMI (r = 0.227) and percentage of trunk fat (r = 0.233). Data from weight-loss program reinforced the results. Partial correlation analysis indicated that obesity-induced oxidative stress and Rac1 expression is a consequence of aberrant glucose-lipid metabolism in overweight adolescents. In conclusion, we provided novel data showing that NADPH oxidase in the monocytes was highly activated by enhancing Rac1 expression in Chinese overweight adolescents and Rac1 may act as a link between obesity and oxidative stress in overweight adolescents.
authors.affiliation: Department of Endocrinology, The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China.
authors.forename: Mingxiao
authors.initials: M
authors.lastname: Sun
authors.forename: Xiuqing
authors.initials: X
authors.lastname: Huang
authors.forename: Yi
authors.initials: Y
authors.lastname: Yan
authors.forename: Junfei
authors.initials: J
authors.lastname: Chen
authors.forename: Zhengzhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Minhao
authors.initials: M
authors.lastname: Xie
authors.forename: Jian
authors.initials: J
authors.lastname: Li
mesh_terms: D050153:Abdominal Fat / Q000378:metabolism; D015502:Absorptiometry, Photon; D000293:Adolescent; D044466:Asian People / Q000706:statistics & numerical data; D050197:Atherosclerosis / Q000453:epidemiology / Q000378:metabolism* / Q000517:prevention & control; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004730:Endothelium, Vascular; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D050356:Lipid Metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism; D050177:Overweight / Q000453:epidemiology / Q000378:metabolism* / Q000517:prevention & control; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
chemical_list: C107953:RAC1 protein, human; D008315:Malondialdehyde; D013482:Superoxide Dismutase; D019255:NADPH Oxidases; D020830:rac1 GTP-Binding Protein