Bernardes Franciane P, Batista Alan T, Porto Marcella L, Vasquez Elisardo C, Campagnaro Bianca P, Meyrelles Silvana S
Laboratory of Translational Physiology, Health Sciences Center, Federal University of Espirito Santo, Vitoria, Brazil.
Federal Institute of Education, Science and Technology (IFES), Vila Velha, ES, Brazil.
Lipids Health Dis. 2016 May 27;15:100. doi: 10.1186/s12944-016-0268-6.
The pharmacological inhibitor of phosphodiesterase 5 (PDE5), sildenafil, is a promising candidate for antioxidant therapy that can result in cardiovascular protection. In addition to its known effects on the cardiovascular system, hypercholesterolemia leads to increased oxidative stress and DNA damage in the bone marrow, which is a non-classical target organ of atherosclerosis. In the present study, we evaluate oxidative stress and assess the effect of genomic instability on cell cycle kinetics in atherosclerotic animals and determine if sildenafil reverses these detrimental effects in bone marrow cells.
Experiments were performed in male wild-type (WT) and apolipoprotein E knockout mice (apoE(-/-)) (9 weeks of age). apoE(-/-) mice were randomly distributed into the following 2 groups: sildenafil-treated (40 mg/kg/day for 3 weeks, n = 8) and vehicle-treated (n = 8), by oral gavage. After treatment, bone marrow cells were isolated to assess the production of superoxide anions and hydrogen peroxide, determine cell cycle kinetics and evaluate the presence of micronucleated cells.
Sildenafil treatment reduced the cytoplasmic levels of superoxide anion (95% decrease, p < 0.05) and decreased hydrogen peroxide (30% decrease, p < 0.05). Moreover, we observed protective effects on the DNA of bone marrow cells, including normal cell cycling, decreased DNA fragmentation and a diminished frequency of micronucleated cells.
Our data reveal that the excessive production of ROS in atherosclerotic mice overcome the DNA repair pathways in bone marrow cells. The novelty of the present study is that the administration of sildenafil reduced ROS to baseline levels and, consequently, reverted the DNA damage and its outcomes in bone marrow cells.
磷酸二酯酶5（PDE5）的药理抑制剂西地那非是抗氧化治疗的一个有前景的候选药物，可带来心血管保护作用。除了其对心血管系统的已知作用外，高胆固醇血症会导致骨髓中的氧化应激增加和DNA损伤，而骨髓是动脉粥样硬化的一个非经典靶器官。在本研究中，我们评估氧化应激，并评估基因组不稳定性对动脉粥样硬化动物细胞周期动力学的影响，以及确定西地那非是否能逆转骨髓细胞中的这些有害作用。
实验在雄性野生型（WT）和载脂蛋白E基因敲除小鼠（apoE(-/-)）（9周龄）中进行。apoE(-/-)小鼠通过口服灌胃随机分为以下2组：西地那非治疗组（40mg/kg/天，持续3周，n = 8）和载体治疗组（n = 8）。治疗后，分离骨髓细胞以评估超氧阴离子和过氧化氢的产生，确定细胞周期动力学，并评估微核细胞的存在情况。
西地那非治疗降低了超氧阴离子的细胞质水平（95%降低，p < 0.05），并降低了过氧化氢水平（30%降低，p < 0.05）。此外，我们观察到对骨髓细胞DNA的保护作用，包括正常细胞周期、DNA片段化减少和微核细胞频率降低。
我们的数据表明，动脉粥样硬化小鼠中活性氧的过量产生超过了骨髓细胞中的DNA修复途径。本研究的新颖之处在于，西地那非的给药将活性氧降低至基线水平，从而逆转了骨髓细胞中的DNA损伤及其后果。
