S ystemic lupus erythematosus (SLE) is a multisystemic chronic autoimmune inflammatory disorder that is associated with a high risk for the development of renal and cardiovascular disease, 1,2 which are major causes of mortality in these patients. 3 It predominantly affects young women of child-bearing age, the same population that is at lowest relative risk of atherosclerotic heart disease. In fact, women with lupus (age, 35-44 years) are >50 times as likely as healthy women without lupus to have a myocardial infarction. 4 Indeed, SLE is characterized by a high incidence of hypertension, 5-7 a wellestablished risk factor for the development and acceleration of atherosclerosis and ischemic heart disease. Oxidative stress and the inactivation of nitric oxide (NO) by vascular superoxide anion (O 2 ·− ) play a critical role in the pathogenesis of endothelial dysfunction, an early event in most cardiovascular diseases, including hypertension. 8,9 Reactive oxygen species (ROS) have been considered as risk and enhancer factors for autoimmune diseases, 10 and oxidation is one of the major factors responsible for atheroma development in this context. Indeed, SLE is a disease characterized by an increased oxidative damage.11-14 Free radical-mediated reactions are implicated in endothelial dysfunction in SLE, 15 and renal oxidative stress plays an important mechanistic role in the development of autoimmune-mediated hypertension.
16Abstract-Hydroxychloroquine has been shown to be efficacious in the treatment of autoimmune diseases, including systemic lupus erythematosus. Hydroxychloroquine-treated lupus patients showed a lower incidence of thromboembolic disease. Endothelial dysfunction, the earliest indicator of the development of cardiovascular disease, is present in lupus.Whether hydroxychloroquine improves endothelial function in lupus is not clear. The aim of this study was to analyze the effects of hydroxychloroquine on hypertension, endothelial dysfunction, and renal injury in a female mouse model of lupus. NZBWF1 (lupus) and NZW/LacJ (control) mice were treated with hydroxychloroquine 10 mg/kg per day by oral gavage, or with tempol and apocynin in the drinking water, for 5 weeks. Hydroxychloroquine treatment did not alter lupus disease activity (assessed by plasma double-stranded DNA autoantibodies) but prevented hypertension, cardiac and renal hypertrophy, proteinuria, and renal injury in lupus mice. Aortae from lupus mice showed reduced endotheliumdependent vasodilator responses to acetylcholine and enhanced contraction to phenylephrine, which were normalized by hydroxychloroquine or antioxidant treatments. No differences among all experimental groups were found in both the relaxant responses to acetylcholine and the contractile responses to phenylephrine in rings incubated with the nitric oxide synthase inhibitor N G -nitro-l-arginine methyl ester. Vascular reactive oxygen species content and mRNA levels of nicotinamide adenine dinucleotide phosphate oxidase subunits NOX-1 and p47 phox were increased in lupus...