Myeloma Unit, San Raffaele Scientific Institute, Milan, Italy.
J Physiol Pharmacol. 2011 Jun;62(3):287-93.
Endothelial mitochondria, the major site of ATP generation, modulate the intracellular dynamics of reactive oxygen species (ROS), which, in turn, control endothelial function. Adequate oxygen (O(2)) supply is required by endothelial cells (EC). Both hypoxia and hyperoxia may favor the overproduction of ROS leading to oxidative stress, mitochondrial damage and endothelial dysfunction. We investigated the capability and mechanisms of Cellfood™ (CF), an antioxidant compound, to modulate O(2) availability and mitochondrial respiratory metabolism and to regulate ROS generated by hypoxia in EC in vitro. Human umbilical vein endothelial cells (HUVEC) and ECV-304 were evaluated for the O(2) consumption using a Clark's electrode. The O(2) consumption rate rose, during the first minutes after CF addition and was associated with increase in mitochondrial oxidative capacity and good cell viability. Similar behaviours were observed when EC were exposed to CF for up to 8 days. The O(2) consumption increased and was accompanied by both intracellular rise of ATP and maintainment of LDH concentration. Hypoxia-induced ROS generation was significantly inhibited by CF, through the up-regulated expression of MnSOD, an anti-oxidant responsible for mitochondrial function preservation. The EC hypoxic response is mediated by the hypoxia master regulator HIF-1alpha whose activation was attenuated by CF, in concomitance with MnSOD up-regulation. Our results suggest a role for CF in improoving respiratory metabolism and in activating anti-oxidant mechanisms in EC, thus preserving endothelial function.
内皮细胞的线粒体是产生 ATP 的主要场所,可调节活性氧物质 (ROS) 的细胞内动态平衡,而 ROS 又反过来控制内皮功能。内皮细胞需要充足的氧气 (O2) 供应。缺氧和高氧都可能导致 ROS 过度产生,从而导致氧化应激、线粒体损伤和内皮功能障碍。我们研究了 Cellfood™(CF)——一种抗氧化化合物——调节 O2 供应和线粒体呼吸代谢以及调节体外内皮细胞缺氧时产生的 ROS 的能力和机制。使用 Clark 电极评估人脐静脉内皮细胞 (HUVEC) 和 ECV-304 的 O2 消耗。CF 添加后的最初几分钟内,O2 消耗率上升,与线粒体氧化能力增加和良好的细胞活力相关。当 EC 暴露于 CF 长达 8 天时,观察到类似的行为。O2 消耗增加,伴随着细胞内 ATP 增加和 LDH 浓度的维持。CF 通过上调 MnSOD(一种负责维持线粒体功能的抗氧化剂)抑制了缺氧诱导的 ROS 生成。EC 的缺氧反应是由缺氧主调节因子 HIF-1alpha 介导的,CF 可减弱 HIF-1alpha 的激活,同时上调 MnSOD。我们的研究结果表明 CF 可改善内皮细胞的呼吸代谢和激活抗氧化机制,从而维持内皮功能。