Laboratory of Translational Physiology, Federal University of Espírito Santo, Vitória, Brazil; Laboratory of Protein Chemistry, Federal University of Espírito Santo, Vitória, Brazil.
Laboratory of Protein Chemistry, Federal University of Espírito Santo, Vitória, Brazil; Research and Development Centre, Ezequiel Dias Foundation, Belo Horizonte, Brazil.
Pharmacol Rep. 2019 Jun;71(3):422-429. doi: 10.1016/j.pharep.2019.01.005. Epub 2019 Jan 6.
High plasma cholesterol levels are able to trigger several pathophysiological events, including inflammation, cell damage and especially oxidative stress. Previously, studies have shown that sildenafil exhibited antioxidant effects in several experimental models. Here we evaluate the role of sildenafil in liver redox equilibrium of apolipoprotein E knockout (apoE-KO) mice.
ApoE-KO mice were divided in two groups: one group received the PDE5 inhibitor sildenafil (40 mg/kg/day) for 3 weeks (apoE-KO + Sil) and was compared to a second group of apoE-KO mice, which received only the vehicle (water) for 3 weeks (apoE-KO). Control group (C57 mice) received only a standard chow diet. At the age of 18 weeks, mice livers were collected for the measurement of intracellular ROS levels and apoptotic cells by flow cytometry analysis, and mitochondria isolation for proteomic analysis.
Compared to the control group, liver cells from apoE-KO presented some typical redox imbalance features: higher levels of intracellular ROS (global oxidative stress ˜60%, superoxide anion ˜82%, and peroxynitrite/hydroxyl radical ˜53%), higher amounts of apoptotic cells (up to ˜19%) and higher mitochondrial intensity of catalase (+339%) and transferrin spots (+914%). After treatment with sildenafil, apoE-KO presented ROS levels and the number of apoptotic cells similar to those observed in C57. In addition, when compared to apoE-KO, apoE-KO + Sil showed lower spots volumes of catalase (-23%) and transferrin (-71%) and up-regulation of urate oxidase (+94%).
The treatment with sildenafil is able to induce beneficial changes in liver mitochondrial protein dynamics, which restores the redox homeostasis contributing to a potential hepatoprotection.
高血浆胆固醇水平能够引发多种病理生理事件，包括炎症、细胞损伤，尤其是氧化应激。先前的研究表明，西地那非在几种实验模型中表现出抗氧化作用。在这里，我们评估西地那非在载脂蛋白 E 基因敲除（apoE-KO）小鼠肝脏氧化还原平衡中的作用。
apoE-KO 小鼠被分为两组：一组给予 PDE5 抑制剂西地那非（40mg/kg/天）治疗 3 周（apoE-KO+Sil），并与另一组接受仅载体（水）治疗 3 周的 apoE-KO 小鼠（apoE-KO）进行比较。对照组（C57 小鼠）仅接受标准的饲料饮食。在 18 周龄时，收集小鼠肝脏进行细胞内 ROS 水平和凋亡细胞的流式细胞术分析，并进行线粒体分离以进行蛋白质组学分析。
与对照组相比，apoE-KO 的肝细胞表现出一些典型的氧化还原失衡特征：细胞内 ROS 水平更高（总氧化应激约 60%，超氧阴离子约 82%，过氧亚硝酸盐/羟自由基约 53%），凋亡细胞数量更多（高达约 19%），以及过氧化氢酶（+339%）和转铁蛋白斑点（+914%）的线粒体强度更高。用西地那非治疗后，apoE-KO 的 ROS 水平和凋亡细胞数量与 C57 相似。此外，与 apoE-KO 相比，apoE-KO+Sil 显示出过氧化氢酶斑点体积减少（-23%）和转铁蛋白斑点减少（-71%），尿酸氧化酶上调（+94%）。
西地那非的治疗能够诱导肝脏线粒体蛋白动力学的有益变化，恢复氧化还原稳态，有助于潜在的肝保护。
