Laboratório de Bioquímica Redox, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
PLoS One. 2009 Nov 16;4(11):e7854. doi: 10.1371/journal.pone.0007854.
Hematophagy poses a challenge to blood-feeding organisms since products of blood digestion can exert cellular deleterious effects. Mitochondria perform multiple roles in cell biology acting as the site of aerobic energy-transducing pathways, and also an important source of reactive oxygen species (ROS), modulating redox metabolism. Therefore, regulation of mitochondrial function should be relevant for hematophagous arthropods. Here, we investigated the effects of blood-feeding on flight muscle (FM) mitochondria from the mosquito Aedes aegypti, a vector of dengue and yellow fever.
METHODOLOGY/PRINCIPAL FINDINGS: Blood-feeding caused a reversible reduction in mitochondrial oxygen consumption, an event that was parallel to blood digestion. These changes were most intense at 24 h after blood meal (ABM), the peak of blood digestion, when oxygen consumption was inhibited by 68%. Cytochromes c and a+a(3) levels and cytochrome c oxidase activity of the electron transport chain were all reduced at 24 h ABM. Ultrastructural and molecular analyses of FM revealed that mitochondria fuse upon blood meal, a condition related to reduced ROS generation. Consistently, BF induced a reversible decrease in mitochondrial H(2)O(2) formation during blood digestion, reaching their lowest values at 24 h ABM where a reduction of 51% was observed.
Blood-feeding triggers functional and structural changes in hematophagous insect mitochondria, which may represent an important adaptation to blood feeding.
血液消化产物会对吸血生物的细胞产生有害影响，因此吸血行为对吸血生物来说是一个挑战。线粒体在细胞生物学中具有多种功能，它既是有氧能量转换途径的场所，也是活性氧（ROS）的重要来源，调节氧化还原代谢。因此，调节线粒体功能对于吸血节肢动物应该是相关的。在这里，我们研究了吸血对埃及伊蚊（Aedes aegypti）飞行肌（FM）线粒体的影响，埃及伊蚊是登革热和黄热病的传播媒介。
方法/主要发现：吸血导致线粒体耗氧量的可逆减少，这一事件与血液消化平行发生。这些变化在吸血后 24 小时（ABM）时最为强烈，此时是血液消化的高峰期，耗氧量抑制了 68%。电子传递链的细胞色素 c 和 a+a(3)水平和细胞色素 c 氧化酶活性在 24 小时 ABM 时均降低。FM 的超微结构和分子分析表明，线粒体在吸血后融合，这与 ROS 生成减少有关。一致地，BF 在血液消化过程中引起了线粒体 H2O2 形成的可逆减少，在 24 小时 ABM 时达到最低值，观察到减少了 51%。
吸血触发了吸血昆虫线粒体的功能和结构变化，这可能是对吸血的重要适应。
