Department of Biology, New Mexico State University, Las Cruces, USA.
Sci Rep. 2018 Aug 29;8(1):13054. doi: 10.1038/s41598-018-31360-2.
Redox reactions play a central role in the metabolism of an organism. It is vital to maintain redox homeostasis in response to the fluctuation of redox shift in various biological contexts. NADPH-dependent reducing capacity is one of the key factors contributing to the redox homeostasis. To understand the redox capacity and its impact on mosquito fecundity and susceptibility to insecticides in Anopheles gambiae, we examined the dynamics of elevated oxidative state via induction by paraquat (PQ) and the inhibition of NADPH regeneration by 6-aminonicotinamide (6AN). In naïve conditions, inherent oxidative capacity varies between individuals, as measured by GSSG/GSH ratio. The high GSSG/GSH ratio was negatively correlated with fecundity. Both PQ and 6AN feeding increased GSSG/GSH ratio and elevated protein carbonylation, a marker of oxidative damage. Both pro-oxidants lowered egg production. Co-feeding the pro-oxidants with antioxidant lycopene attenuated the adverse effects on fecundity, implying that oxidative stress was the cause of this phenotype. Pre-feeding with 6AN increased insecticide susceptibility in DDT resistant mosquitoes. These results indicate that oxidative state is delicate in mosquitoes, manipulation of NADPH pool may adversely affect fecundity and insecticide detoxification capacity. This knowledge can be exploited to develop novel vector control strategies targeting fecundity and insecticide resistance.
氧化还原反应在生物体的代谢中起着核心作用。为了应对各种生物环境中氧化还原变化的波动，维持氧化还原平衡至关重要。NADPH 依赖性还原能力是导致氧化还原平衡的关键因素之一。为了了解氧化还原能力及其对冈比亚按蚊生殖力和对杀虫剂敏感性的影响，我们通过百草枯（PQ）诱导和 6-氨基烟酰胺（6AN）抑制 NADPH 再生来检查氧化状态的动力学。在初始条件下，通过 GSSG/GSH 比值测量，个体之间存在固有氧化还原能力的差异。高 GSSG/GSH 比值与生殖力呈负相关。PQ 和 6AN 喂养均增加 GSSG/GSH 比值和蛋白质羰基化，这是氧化损伤的标志物。两种促氧化剂均降低产卵量。用抗氧化剂番茄红素共喂养促氧化剂可减轻对生殖力的不利影响，这表明氧化应激是这种表型的原因。用 6AN 预喂养增加了对 DDT 抗性蚊子的杀虫剂敏感性。这些结果表明，氧化状态在蚊子中很脆弱，NADPH 池的操纵可能会对生殖力和杀虫剂解毒能力产生不利影响。这些知识可以被利用来开发针对生殖力和杀虫剂抗性的新型蚊虫控制策略。
