Ferreira Guilherme Silva, Pinto Paula R, Iborra Rodrigo T, Del Bianco Vanessa, Santana Monique Fátima Mello, Nakandakare Edna Regina, Nunes Valéria S, Negrão Carlos E, Catanozi Sergio, Passarelli Marisa
Laboratorio de Lipides, Laboratorio de Investigaçao Medica - 10 (LIM-10), Hospital das Clinicas (HCFMUSP), Faculdade de Medicina, Universidade de Sao PauloSao Paulo, Brazil.
Unidade de Reabilitação Cardiovascular e Fisiologia do Exercício, Instituto do Coração InCor da Faculdade de Medicina, Universidade de São PauloSão Paulo, Brazil.
Front Physiol. 2017 Sep 5;8:644. doi: 10.3389/fphys.2017.00644. eCollection 2017.
Oxysterols are bioactive lipids that control cellular cholesterol synthesis, uptake, and exportation besides mediating inflammation and cytotoxicity that modulate the development of atherosclerosis. Aerobic exercise training (AET) prevents and regresses atherosclerosis by the improvement of lipid metabolism, reverse cholesterol transport (RCT) and antioxidant defenses in the arterial wall. We investigated in dyslipidemic mice the role of a 6-week AET program in the content of plasma and aortic arch cholesterol and oxysterols, the expression of genes related to cholesterol flux and the effect of the exercise-mimetic AICAR, an AMPK activator, in macrophage oxysterols concentration. Sixteen-week old male apo E KO mice fed a chow diet were included in the protocol. Animals were trained in a treadmill running, 15 m/min, 5 days/week, for 60 min (T; = 29). A control group was kept sedentary (S; = 32). Plasma lipids and glucose were determined by enzymatic techniques and glucometer, respectively. Cholesterol and oxysterols in aortic arch and macrophages were measured by gas chromatography/mass spectrometry. The expression of genes involved in lipid metabolism was determined by RT-qPCR. The effect of AMPK in oxysterols metabolism was determined in J774 macrophages treated with 0.25 mM AICAR. Body weight and plasma TC, TG, HDL-c, glucose, and oxysterols were similar between groups. As compared to S group, AET enhanced 7β-hydroxycholesterol (70%) and reduced cholesterol (32%) in aorta. In addition, exercise increased (54%), (75%), (70%), (40%), and (51%) mRNA. In macrophages, the activation of AMPK followed by incubation with HDL increased (52%) and (220%) and decrease (19%), (47%) and 7α-hydroxycholesterol level. AET increases 7β-hydroxycholesterol in the aortic arch of dyslipidemic mice, which is related to the enhanced expression of . In addition, the increase and reduction of and in trained mice may contribute to enhance levels of 27-OH C. Both oxysterols may act as an alternative pathway for the RCT contributing to the reduction of cholesterol in the aortic arch preventing atherogenesis.
氧化甾醇是一类生物活性脂质，除了介导炎症和细胞毒性从而调节动脉粥样硬化的发展外，还能控制细胞内胆固醇的合成、摄取和输出。有氧运动训练（AET）可通过改善脂质代谢、逆向胆固醇转运（RCT）以及动脉壁中的抗氧化防御作用来预防和逆转动脉粥样硬化。我们在血脂异常的小鼠中研究了为期6周的AET方案对血浆和主动脉弓中胆固醇及氧化甾醇含量的影响、与胆固醇通量相关基因的表达，以及运动模拟物AICAR（一种AMPK激活剂）对巨噬细胞中氧化甾醇浓度的影响。实验方案纳入了16周龄、喂食普通饲料的雄性载脂蛋白E基因敲除（apo E KO）小鼠。动物在跑步机上以15米/分钟的速度跑步训练，每周5天，每次60分钟（T组；n = 29）。设立一个不运动的对照组（S组；n = 32）。分别采用酶法技术和血糖仪测定血浆脂质和葡萄糖。通过气相色谱/质谱法测量主动脉弓和巨噬细胞中的胆固醇及氧化甾醇。采用RT-qPCR法测定参与脂质代谢的基因表达。在经0.25 mM AICAR处理的J774巨噬细胞中测定AMPK对氧化甾醇代谢的影响。两组之间的体重、血浆总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-c）、葡萄糖和氧化甾醇水平相似。与S组相比，AET使主动脉中7β-羟基胆固醇增加了70%，胆固醇减少了32%。此外，运动使 、 、 、 和 的mRNA水平分别增加了54%、75%、70%、40%和51%。在巨噬细胞中，AMPK激活后再与高密度脂蛋白（HDL）孵育，使 和 分别增加了52%和220%，并使 、 和7α-羟基胆固醇水平分别降低了19%、47%。AET增加了血脂异常小鼠主动脉弓中的7β-羟基胆固醇，这与 的表达增强有关。此外，训练小鼠中 和 的增加及减少可能有助于提高27-羟基胆固醇（27-OH C）的水平。这两种氧化甾醇可能作为RCT的替代途径，有助于降低主动脉弓中的胆固醇，预防动脉粥样硬化的发生。
